
I also use AIFF files but I don't have any problems with the tags, just the artwork (I've posted this a couple of months ago... http://forums.pioneerdj.com/entries/20242306-no-artwork-on-aiff-files).
I import my AIFF from iTunes via the bridge and everything works fine except for the artwork... :(
Note: I fix all tags in iTunes before I import the tracks to rekordbox!