I have the 2g iphone and I was using a custom 2.0 firmware that I created with winpwn 2.0. One day I tried to open up one of the apps I downloaded from itunes and initially it will open but within 2 or 3 seconds it closes. I tried to open every first party app that I had and non of them work, all of the apps from cydia still work.
So I tried upgrading to custom FW 2.02, still did the same thing. I downgraded back to 2.0, same thing. Ok, now I am back at custom 2.02 and I still cant open any apps. Any suggestions?