[XP] Strange USB problem

This problem just started happening about 2 weeks ago and I can't figure out what is causing it. What happens is all of the sudden ALL of my USB devices stop working at the same time. Its like Windows is trying to detect them or something becuase they will stop and my mouse will flash a couple times and then start to work again. As I am typing this it just happened again....very annoying. I am not sure if one of my devices is bad or possibly the MB or power supply is on its way out? Has anyone ever experienced this before? I guess I can try unplugging one of the devices at a time and see if I can find one that is a problem.

I think disconnecting the devices one at a time would be a good place to start. I have a nasty feeling that this could be a motherboard problem though :(

Yeah I am thinking it may be the MB as well. I am going to unplug all the USB devices and see what happens.