Applications lost all of a sudden..

Hey there,

I have a problem with my iphone 4S.

That was the third time it happened yesterday, so I decided to ask.
Twice, when I took a look at my phone, I realized that all the downloaded applications are lost. But yesterday, when I was using my phone, all of a sudden, the game I was playing quit and then I realized once more all the downloaded applications are gone.

I can "fix" it by resetting my iphone and restoring it with the last backup but obviously I do not like to restore my phone everyweek. I am looking for an answer to my problem. Are there anyone facing the same problem? If any, what can I do?

Thanx in advance..

That is highly anomalous. Have you done anything with it, like open it up or jailbreak it?