Googling around, I found some posts here and there discussing the problem, but no workaround (apart from reformatting the drive using HFS+). In brief, I found that sharing FAT32 (and NTFS) partition is possible and not so hard to do; you just need to use Samba.
- In terminal, edit the file /etc/smb.conf to add the share: sudo pico /etc/smb.conf
- Add the following to the end of smb.conf (assuming your partition/drive is mounted on /Volumes/myfat32hd):
Then save the file (in pico, you can type Control-X, then answer Y). (You can tailor the share permissions to your liking. In this example, I created a public world-writable share).[MyFatShare] path =/Volumes/myfat32hd public=yes writable=yes browseable = yes only guest=yes - Enable Windows sharing in the Sharing System Preferences panel. This will enable and run Samba file sharing. (If Samba is already running, it checks smb.conf every minute, so you don't need to stop and restart the service to have it find the new share.)

