Hi Goa,
Certainly sounds like the problem I had, mine was caused by a ? in the filename that windows didn't like.
However I simply renamed the file and it was OK.
I am running vista, I don't know but this may have made the difference as renaming was not a problem.
Jack

I have linux on cd that I got from the IT guys at work, you can boot directly from this cd and do all sorts of things by passing windows.
perhaps something like this may help

with a linux live CD you don't have to 'change to linux', just boot from the CD, use it to change the filenames on your hard drive, then take the CD out and restart back into Windows, if you wanna try it then you can get a live CD here: http://www.ubuntu.com/getubuntu/download 

have you tried renaming the file from the command line?  Start > Run > CMD > OK > REN really_long_filename short_filename

edit:

I should have said, the filename in command prompt will display in '8.3 format' for DOS compatibility, making it easier to edit, if you open command prompt and change to the directory with the files in, then do a 'dir', you'll see the filenames will look different to how they look in Windows Explorer, for instance 'thisisaverylongfilename.txt' will show as 'THISIS~1.TXT', so to rename it just type 'ren THISIS~1.TXT new_filename.txt'

That's it.  With Windows, it's the length of the file name, plus the path length that counts, so C:\My Documents\Live Music\Ukele Classics\George Formby\Accrington Palais1935-07-06\Disc 01Track 01 When I'm Cleaning Windows.flac  would undoubtedly cause problems, but if you were to move the folder to the desktop, or straight to the C drive, you should be ok