Are they 'not there' as in you're not seeing previews but gray squares, or are they 'not there' as in there are ? in the upper right of each frame in the Library module?
Nada. Zip. No grayed out squares, no nothing.
If I search (thankfully I remembered some of the names I gave final process treatments), the search results still lists them as being in Libraries>Pictures>Processed RAW, and I can back my way into where they are by doing the 'folder up' bit, but they simply will not show up if I just click on the folder itself.
That, and when I opened up LR4 Beta, there simply was nothing imported into it anymore. I had to go through some hoops to get them back in.
If this is indicative of the program in general, I'll never buy a damned thing from DxO.