Massive 5.5GBs of "other"!

Don't suppose you've got any films etc in avplayerhd or another app like that??

I wondered what the hell that was. I had that too once...it actually said I was over capacity by like 7GB. Which made no sense. I restored it and it was fine after that, but I had a hunch I over-reacted. I'd love to find out why it did this, and what to do if it happens again. (Without restoring it, at least)

Is it jailbroken by any chance? If so, do you have an app called iFile installed?