Well, I managed to load GTA LCT game and freezed while loading the game. So it gives me message that no Memory Stick found in NFS: Carbon and so in Street Fighter Alfa. I have MS in. What should I do?

first, where did u get your memory stick?

second, what brand is it?

Sony 1GB Memory Stick Pro Duo.
Came with Gigapack.

Try removing the mem stick, and re-booting your PSP system. Then, maybe a format and re-transfer the games, devhook or any other home brews on your memory stick. (you will loose all data if you format your mem stick- dont try it yet unless you can put all the files needed back on). Try downloading other games and testing them out. (visit the user contributed download ISO section).
Or contact sony and say every time you go to accesses your memery stick.... in the video menu, music and photo menus it crashes. If they want your mem stick then format and remove all data on there. Hopefully you will receive a new one!
Good luck.

I also faced similar problems before .

First time is corrupted ISO causing the games unable to load and PSP freeze . Simply re-copy the file again to the memory stick and it works fine.

Second time , bought a new memory stick , my pc unable to detect the MS at all , (I'm using the usb Sony memory vault which got the memory stick slot) . Insert to my psp also cannot detect . So confirm is the Memory stick spoilt . Need to change to a new one because under warranty.

So it is very important to check whether it is memory stick faulty or not . If partial games are working while others not , most probably need to delete the corrupted games and copy all over again.