Well, most ftp daemon use the unix file right and ownership. Fat32 doesn't support right or ownership change, of course. Habitually, I'm mounting my Fat32 partition with read&write for the users group, so MY personnal user (the user I'm personnaly using instead of root...) can modify the partition.
I have a dual boot system (I need windoze sometime to do my university homework) all my "important" (homeworks, music files, movie, archive) files are on the FAT32 partition, so I'm able to use is either in linux or windoze.
But I want my "ftp user" (mostly friend, but also some people I don't know or trust too much) to be able to write in some directory of that partition, but to have read only right in some other directory... Because I can only give a "global" file right and ownership to Fat32 partition at mount, it's very hard to do.
So I'm looking for a ftp daemon able to put right and ownership on Fat. I'm currently using one, but the last update of the software was made by his author 3 long years ago, and he stop working on it then. So I'm not really sure I can trust this software.