Can't get app store app's to work !!!! OS 3.0

[dc5prb]

I upgraded to 3.0 and jailbroke the iphone. I have had no problems. But now all my apple app's from the store won't load. they just open and close. I have restored from a back up I have deleted an app and re-installed it and have re-synced and I just can't get them to load everything else works except the app store apps even if I get a new app it just does not work. does any one know why this is

ok this is weird I am going thru the phone and I was trying to see if any of the apps worked and none of them did but I clicked on swap tunes and it switched and now my apps work I don't know what will happen if I switch back

[kwall]

You never restore from a backup. I do not know why everyone insists on doing this.

[GrabYourWeapons]

Plug your phone into your computer and make sure the computer is authorized, or sign out of your iTunes account and resign in.