Hello and sorry for the bother.

I have 2 PSPs, a fat one and a slim one (but for now let's focus on the slim). Both share the same problems probably because I used the same FW updates for both. The only difference for now is that for now the fat is still on 6.39 CFW.

Several games freeze while playing randomly* when the MS-reading-light (or thatever the small light in the left side of the psp is called that is not the wifi) flashes (BlazBlue CSII, Kenka Bancho) or simply don't load at all or freeze after the into movie (Persona 1 + 3) and the Slim won't read any real UMDs (tried DarkStalkers and Dead Head Fred, it says disk read error. DHF is fresh out of the box).
How do I fix it? It used to work fine 1 year ago but after 2-3 firmware upgrades (because P3P and P:R wouldn't work from the first place) it can barely play any games. It also went semi-brick yesterday but after the recover nothing was improved.

It's a PSP Slim, I don't remember which MB but when I got it, it had permanent patch to load CFW.
current CFW is 6.60 ME-1.8.

It really all started because I couldn't play the Persona games and BB:CC2. Before the firmware update it had no problem reading UMD and now it says it can't. What can I do?

*sometimes (indicated when I plug the MS to the PC) it seems like the MS couldn't be read at all. Perhaps that what screws the games. But it never happened to me with BB:CT or Project Diva or Badman or any other games. For some reason I problem only with the second BlazBlue.