Question : unload view when switching tab

I am developing a tabBarControlled iPhone application with multiple views. I have found that when I switch from one view to another, the view you come from does not stop executing what it was doing.

What I want basically is that everytime that I switch view, the view is unloaded, and gets re-loaded when the user gets back to that tab.

How can this be done?

Thanks!

Answer : unload view when switching tab

Cycled the power off for a day, device came back up and went through a lengthy self test.  Problem solved, strange though.