Phantom data taking up storage space

As you can see in this picture (i.imgur.com/Q0ZZdUO.png) my phone's internal storage is about 11 GB, however the combined storage space of everything listed below is less than 6 GB. I know personally that I have not put much of anything onto the internal storage, so what does the phone think is taking up the other 5 GB, and how can I fix it?
I'm using this ROM btw:
http://forum.xda-developers.com/show....php?t=2771440