I'm using BFNav 1.0.1 would that have anything to do with it?
They're normal 'default' images, none of them are external or video thumbs.
I followed your instructions when installing the theme, moved the widgets out, exported the settings. But reimporting them didn't seem to go as planned. I did however eventually get it back, but I had to import a couple times first. It was somewhat strange, like with each import one or two things would restore. I'm curious if it's a caching issue now, though WP-SuperCache not supposed to cache for logged in users, APC however I think is indescriminate and doesn't care who you are and provides you with cached Opcode regardless.
The navigation bars had disappeared from the admin area, but that was because I reset everything. Through importing over and over again I did get them back however.