i used "flashfxp v2.0 rc3 build879 cracked version.rar" one time, on one ftp the files were ok but on another all got corrupt (54 KB more than on the server :/ ) i don't use flashfxp so i can't help you more than this, but i'm sure someone else can tell you more
cuteftp pro did download all these files without problems
it's my favorite and i'm using it for some time now, i can recommend it to everyone
FortiTude