UPDATE: As said before it works fine with this 8GB stick on FAT32, but using download master with torrents only works if they're under 1GB or something. Every time I try to get a 2GB+ torrent the router crashes a few seconds after I start the download - file sharing, web interface, etc.
I wonder if this has something to do with the FAT32 file system implementation or the download master software just can't handle it? Some torrents I've tried had more files of 1GB and it still crashed...
I'll give it a go with EXT2 and see what happens