iTunes does not detect a specific iPhone. Please help!

Recently upgraded to iTunes v11 and since then iTunes does not detect my iPhone 4 when plugged into my Windows 7 computer. windows can see the memory card on the phone (like it is a camera) and iTunes is able to detect and sync my iPod Touch - but iTunes does not see the iPhone. My windows 8 laptop picks up all the devices without issue.

Since first having the problem, I have reset the iPhone (as I now have an iPhone5) and also uninstalled iTunes and then re-installed it from the ooficial Apple donwload Setup. The problem persists.

I have tried restarting the computer and also have stopped and restarted the Apple Device Service (as per other threads) although as the iPod is being detected I did not expect this to solve the problem - and it didn't.

Any assistance would be greatly appreciated.