Folders missing from Windows Explorer on Network USB Hard Drive

Windows XP Home SP2. I have a networked (shared) 250 MB USB hard drive
formated in Fat32 (I have Macs on this network). I store all of My Music on
this networked drive. Recently, I accessed the drive via Windows Explorer
and noticed that I cannot see all of the subfolders under My Music folder. I
have many folders (9,000+), but the list appears truncated (there are no
folders that begin with the letter "a" for example - the list starts at the
"b's"). I have tried unhiding all folders on this drive and made sure none
were read only. The "missing" folders still don't display. The files in
these folders still exist - I am able to play the music via Itunes. Looking
at the file (MP3) info in Itunes gives a valid path to the file and it plays
normally - I just can't see them in Windows Explorer. Any ideas?