There is no other in WP after the amber update, the Nokia storage check is outdated and useless now, I know many will argue, hear me out before you all stat debating,
I have gdr3 preview, installed moliplayer and loaded vids to my phone in the camera role, this were file formats the phone could not recognize, flv, vob etc, after loading the vids, storage check showed that my other had grown from 432mb to 10gb which was ridiculous because the increase was because of the videos I loaded but the Nokia tool could not recognize them as media files, I checked using Microsoft's phone storage in gdr3 which showed an increase in media files as a result of the videos, I deleted the videos and Nokia's tool showed a decrease to the original size,
Check if you loaded any unsupported files, don't people wonder why a reset clears the other), Nokia should update the tool or remove it, its outdated.