Problem w/ iphone 4 after updating firmware from 4.2 to 4.3.2

Whenever I tap an app, it will flash on for an instant then the homescreen reappears? It only does this for the aftermarket apps, not the original Apple apps. I can make calls and check email.

I did a hard reset, still the same result?

After more research, just had to download and install a new app; that fixed the problem. Somehow, that restores the password to the other apps.