Don't think I have an awnser for you but I did spend some time looking around.
Is your Partion Magic bundled with a Norton (Symantec) product? I see they took over Partion Magic at least from version 8. Anyway saw this post:
"One partitioning tool that I have used is Partition Magic
for years now, only lost two partitions one I got back
using nortion utilities, the other I didn't care about."
google
As to the particular error, found this:
Error 1555 Internal file number does not match position
Cause: The file number stored in the header of an NTFS file does not match the file's position in the file table.
Solution: This problem can be resolved by running CHKDSK /F on the affected drive. Sometimes it must be run multiple times to resolve this error. If running under Windows 2000/XP a CHKDSK /P can be run from the recovery console to fix files that may not otherwise be fixable. CHKDSK /P from the recovery console is the same function as CHKDSK /F from the command prompt in Windows.
Also found this regarding Partion Magic 8:
Symantec Support
Just wondering if a System Restore would fix this? I don't know.
Anyway I tried
Good luck!