OK ...
I installed the updated version of HJT, ran a scan & then checked & fixed the items you listed.
Unfortunately the problem still seems to be occurring.
I've rerun HJT & my logfile follows: -
Logfile of HijackThis v1.99.1
Scan saved at 5:35:20 PM, on 17/03/2006
Platform: Windows 2000 SP4 (WinNT 5.00.2195)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)
Running processes:
C:\WINNT\System32\smss.exe
C:\WINNT\System32\winlogon.exe
C:\WINNT\system32\services.exe
C:\WINNT\system32\lsass.exe
C:\WINNT\system32\svchost.exe
C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
C:\WINNT\system32\spoolsv.exe
C:\Program Files\Common Files\Symantec Shared\ccProxy.exe
C:\WINNT\System32\svchost.exe
C:\Program Files\Ahead\InCD\InCDsrv.exe
C:\Program Files\Norton Internet Security\Norton AntiVirus\navapsvc.exe
C:\WINNT\system32\regsvc.exe
C:\Program Files\Norton Internet Security\Norton AntiVirus\SAVScan.exe
C:\WINNT\system32\MSTask.exe
C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe
C:\Program Files\Analog Devices\SoundMAX\SMAgent.exe
C:\WINNT\system32\stisvc.exe
C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe
C:\WINNT\System32\Tablet.exe
C:\WINNT\System32\WBEM\WinMgmt.exe
C:\WINNT\System32\mspmspsv.exe
C:\WINNT\system32\svchost.exe
C:\WINNT\Explorer.EXE
C:\WINNT\System32\sistray.EXE
C:\Program Files\Analog Devices\SoundMAX\SMTray.exe
C:\PROGRA~1\Java\J2RE14~1.2\bin\jusched.exe
C:\Program Files\Ahead\InCD\InCD.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\Common Files\Symantec Shared\ccApp.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktopIndex.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\WINNT\system32\internat.exe
C:\Program Files\Plaxo\2.3.4.2\InstallStub.exe
C:\Program Files\WinZip\WZQKPICK.EXE
C:\WINNT\webshots.scr
C:\Program Files\Google\Google Desktop Search\GoogleDesktopCrawl.exe
C:\Program Files\Outlook Express\MSIMN.EXE
C:\Program Files\HijackThis\HijackThis.exe
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page =
http://www.optusnet.com.au/
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Int ernet Settings,ProxyServer = proxy.qut.edu.au:3128
R3 - Default URLSearchHook is missing
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: Web assistant - {9ECB9560-04F9-4bbc-943D-298DDF1699E1} - C:\Program Files\Common Files\Symantec Shared\AdBlocking\NISShExt.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar1.dll
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Program Files\Norton Internet Security\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINNT\system32\msdxm.ocx
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar1.dll
O3 - Toolbar: Web assistant - {0B53EAC3-8D69-4b9e-9B19-A37C9A5676A7} - C:\Program Files\Common Files\Symantec Shared\AdBlocking\NISShExt.dll
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Program Files\Norton Internet Security\Norton AntiVirus\NavShExt.dll
O4 - HKLM\..\Run: [Synchronization Manager] mobsync.exe /logon
O4 - HKLM\..\Run: [SiS Tray] C:\WINNT\System32\sistray.EXE
O4 - HKLM\..\Run: [Smapp] C:\Program Files\Analog Devices\SoundMAX\SMTray.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] C:\PROGRA~1\Java\J2RE14~1.2\bin\jusched.exe
O4 - HKLM\..\Run: [NeroCheck] C:\WINNT\system32\\NeroCheck.exe
O4 - HKLM\..\Run: [InCD] C:\Program Files\Ahead\InCD\InCD.exe
O4 - HKLM\..\Run: [Google Desktop Search] "C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe" /startup
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Common Files\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [URLLSTCK.exe] C:\Program Files\Norton Internet Security\UrlLstCk.exe
O4 - HKCU\..\Run: [internat.exe] internat.exe
O4 - HKCU\..\Run: [PlaxoUpdate] C:\Program Files\Plaxo\2.3.4.2\InstallStub.exe -a
O4 - Startup: Webshots.lnk = C:\Program Files\Webshots\Launcher.exe
O4 - Global Startup: Adobe Gamma Loader.lnk = C:\Program Files\Common Files\Adobe\Calibration\Adobe Gamma Loader.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office\OSA9.EXE
O4 - Global Startup: WinZip Quick Pick.lnk = C:\Program Files\WinZip\WZQKPICK.EXE
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Restrictions present
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Control Panel present
O8 - Extra context menu item: &Google Search - res://c:\program files\google\GoogleToolbar1.dll/cmsearch.html
O8 - Extra context menu item: &Translate English Word - res://c:\program files\google\GoogleToolbar1.dll/cmwordtrans.html
O8 - Extra context menu item: Backward Links - res://c:\program files\google\GoogleToolbar1.dll/cmbacklinks.html
O8 - Extra context menu item: Cached Snapshot of Page - res://c:\program files\google\GoogleToolbar1.dll/cmcache.html
O8 - Extra context menu item: Similar Pages - res://c:\program files\google\GoogleToolbar1.dll/cmsimilar.html
O8 - Extra context menu item: Translate Page into English - res://c:\program files\google\GoogleToolbar1.dll/cmtrans.html
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\WINNT\System32\msjava.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\WINNT\System32\msjava.dll
O10 - Unknown file in Winsock LSP: c:\progra~1\aventail\connect\asnsp.dll
O10 - Unknown file in Winsock LSP: c:\progra~1\aventail\connect\aslsp.dll
O10 - Unknown file in Winsock LSP: c:\progra~1\aventail\connect\aslsp.dll
O10 - Unknown file in Winsock LSP: c:\progra~1\aventail\connect\aslsp.dll
O16 - DPF: {01010E00-5E80-11D8-9E86-0007E96C65AE} (SupportSoft SmartIssue) - http://www.symantec.com/techsupp/asa/ctrl/tgctlsi.cab
O16 - DPF: {01012101-5E80-11D8-9E86-0007E96C65AE} (SupportSoft Script Runner Class) - http://www.symantec.com/techsupp/asa/ctrl/tgctlsr.cab
O16 - DPF: {08BEF711-06DA-48B2-9534-802ECAA2E4F9} (PlxInstall Class) - https://www.plaxo.com/down/latest/PlaxoInstall.cab
O16 - DPF: {1F2F4C9E-6F09-47BC-970D-3C54734667FE} (LSSupCtl Class) - http://www.symantec.com/techsupp/asa/ctrl/LSSupCtl.cab
O16 - DPF: {288C5F13-7E52-4ADA-A32E-F5BF9D125F98} (CR64Loader Object) - http://www.miniclip.com/puzzlepirates/miniclipGameLoader.dll
O16 - DPF: {C02226EB-A5D7-4B1F-BD7E-635E46C2288D} (Toontown Installer ActiveX Control) - http://download.toontown.com/sv1.0.13.14/ttinst.cab
O16 - DPF: {CE28D5D2-60CF-4C7D-9FE8-0F47A3308078} (ActiveDataInfo Class) - http://www.symantec.com/techsupp/asa/ctrl/SymAData.cab
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccEvtMgr.exe
O23 - Service: Symantec Network Proxy (ccProxy) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccProxy.exe
O23 - Service: Symantec Password Validation (ccPwdSvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccPwdSvc.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\ccSetMgr.exe
O23 - Service: Logical Disk Manager Administrative Service (dmadmin) - VERITAS Software Corp. - C:\WINNT\System32\dmadmin.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: InCD File System Service (InCDsrv) - AHEAD Software - C:\Program Files\Ahead\InCD\InCDsrv.exe
O23 - Service: iPodService - Apple Computer, Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: Norton AntiVirus Auto Protect Service (navapsvc) - Symantec Corporation - C:\Program Files\Norton Internet Security\Norton AntiVirus\navapsvc.exe
O23 - Service: SAVScan - Symantec Corporation - C:\Program Files\Norton Internet Security\Norton AntiVirus\SAVScan.exe
O23 - Service: ScriptBlocking Service (SBService) - Symantec Corporation - C:\PROGRA~1\COMMON~1\SYMANT~1\SCRIPT~1\SBServ.exe
O23 - Service: Symantec Network Drivers Service (SNDSrvc) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe
O23 - Service: SoundMAX Agent Service (SoundMAX Agent Service (default)) - Analog Devices, Inc. - C:\Program Files\Analog Devices\SoundMAX\SMAgent.exe
O23 - Service: Symantec Core LC - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe
O23 - Service: TabletService - Wacom Technology, Corp. - C:\WINNT\System32\Tablet.exe
Thanks for your help.