Getting Locked in Apps

[iamjamieq]

Since I last restored my iPhone 4, and then jailbroke it and installed a long list of Cydia packages, I have a problem that happens every so often where the Home button doesn't exit out of an app. Its like I get locked in. I can double click and use the multitask bar to switch apps, but can't exit out of any app I switch to. The only way to get it to close the app is by locking and then unlocking the phone.

Does anyone else have this problem? If so, does anyone know why it is happening? Possibly an app messing with my phone?

[Cowboy]

My lockscreen sometimes does it i am guessing it has to do with overloading the phone and slowing down the memory