This also happens when an app doesn't install properly. It happened to me when installing Infinity Blade. My "other" section jumped to over 2gb. I deleted the app, then reinstalled and the "other" space was reduced.
You can go into settings on the IPT and then see a list of apps and the space they consume. Then, click on an individual app to see how much of that space is "other" data. If you see any big offenders, delete them and reinstall them.