Try rebuilding system data base, but be sure to backup before you do this, or you may loose your data. If your ps3 has warranty then you should phone up sony
This is just a seperate question from this thread, but can I backup data on my ps3? Example: I have 50 Gigs I want to back up. Can I just back up onto the ps3 I am using, or do I need to get a seperate hard drive?