iPhone not connecting to iTunes

Recently I updated iTunes as per the reminder that pops up and since then i have not been able to connect to iTunes with my iPhone 4. When i plug in the USB it makes the beep sounds for a conenction and the iPhone charges but nothing happens in iTunes - I even get that little pop up window that says do you want to open files in windows explorer etc, but no response from iTunes.

Does anyone have any ideas or experiences the same thing?

Assistance would be much appreciated.