Why are 2 computers all of a sudden not detecting iPhone?

System: Windows XP (I know, I know)
iPhone: gen. 1

Problem: approximately 3900 pictures stuck on iPhone, which is invisible to both a desktop and a laptop

Weird: it is detected by iTunes

It doesn’t show up under scanners/cameras, and when I open up Corel Photo Album that program can’t detect it’s connected either.

Troubleshooting I’ve tried so far:
– started and stopped the processes Bonjour and Apple Mobile device
– switched to different USB ports, different USB cable
– restarted both computers
– researched apple discussion boards
– googled
– sighed heavily

So, do you have any ideas? Ever have this happen before? Usually I just download the pics using Corel, without any issues. Help…