Aha, I know what the problem is (error 40). Im too fast :-)
Cleared the runtime again and copyed everything back. Opened P8 and if I now wait for a long time the items seems to be found. Just way slower now than PoserPro as I can't see when the search is over. I was trying to access and search folders that wasn't finished by the search.
A project Im working on has many folders and files. It took a long time to find but in the end it was found.
So sorry - me bad. The search seems to work, but It just take a long time to get through the search. 28 sec. to put a time on it which is a very very long time for me compared to PoserPro.
I also tryed to adjust the thumbnail size but P8 crashed. Again I waited for the search to finish and this time it didn't crash. So a suggestion would be to only have the library window open when a search is completed - or atleast a notification that the search is still in progress.