Might help....
First time forum-er guys, so sorry if I break the etiquette.
I had the exact same problem, and previously I had used my iPod as an external drive storage. Of course, I've since deleted all those files, so there weren't any.
However, I do find that with any external drive, deleting the files (ie moving to trash - I'm a mac user), doesn't actually clear up any space. I have to have the external drive physically plugged in when I choose "Empty Trash".
Tried that, and viola, my "other" category has returned from the menacing 6GB to nothing.
Thanks for your help, hope this helps out someone else.