browser cannot display page/connection excellent

Windows XP SP2 /I.E. 6 SP2/ Wireless connection LAN( home)/ /HP Pavilions zv5000 Laptop

wireless connection is showing excellent quality - Browser will work and load any page from internet for a matter of minutes - usually under an hour - as long as 50 to 58 min. but as short as 15 minutes - it will stop loading pages with the "The Page Cannot be displayed..." error dialogue- at that point I cannot even ping- it says server cannot be found or that there is not a connection.

I have turned off all firewalls, I have deleted all temp. internet files-

a symptom that i noticed occurs exactly when the inability to log on happens is that a balloon appears on the bottom icon bar for the wireless connection status -letting me know I am connected - even though it has been for quite a while at that point - and there is an indication of disc activity that occurs just before (disc activity light blinks)

I cannot figure this out I have looked all through the Microsoft Support and numerous other sites to no avail. Nothing seems to work - I have a successful wireless TCP/IP connection the Router and DSLmodem are working great - I have other desktops connected via ethernet LAN network/DSL internet with no issues/problems at all (2 Apple workstations and an Apple ibook) (I do not have the Windows XP networking with the Apples)

Please advise -

thanks ScottM

I needed to add the only way I have found to correct this problem is to Restart - then the browser resumes working fine until it stops loading pages again within the hour time frame as described above.