a while ago, i needed to change my external hard drive's file system from ext3 to fat32, to use it in windows, which i did the simple way: i shrunk the ext3 partition, made a fat32 partition, copied the files over, removed the ext3 and made the fat32 bigger. unfortunately, while gparted was making the partition larger, my computer shut down. i lost all my files and the partition messed up immediately. i made a new fat32 partition, after deleting the old one, but noticed that gparted was showing 100 gigs already in use (???). so now i have a 300 gb hard drive with only 200 gb i can use; i ran df to make sure gparted wasn't messing up, but indeed it shows the partition as being only 200 gigs in size. i haven't tried making any other kind of partition yet, such as ext3, for fear of losing my files again, and because it wouldn't be permanent anyway, because i need those files in windows and stupid microsoft won't make their OS ext3 compatible.
i don't know if anyone else has had that problem, or if you know what i could do, but any help is greatly appreciated

I'm sorry that I don't have a solution for you, but I'd like to point out that you can access ext3 partitions from Windows. In fact, a quick search will result in multiple solutions.

It appears the files are in place, but their directory entries are not. Either that or files have space reserved for them.

testdisk - recovers lost partitions
photorec - recovers lost files

Enjoy!