Hi
I make home videos, so pulling large amounts of videos of an iDevice is important! Try this:
1. Plug in your iPhone
2. Open Computer and double-click on the iPhone
3. Click on DCIM
4. Click on the folder (it changes according to your device)
5. Either highlight and drag the videos/photos to your desktop or into the iTunes Movies section
Optionally you can stop the AppleMobileDevice.dll in Task Manager and see if you can find it in computer, or possibly just the opposite is the service isn't started! Let me know if it works, and if not i'll try to help you in any way i can!