Sounds like the exact same problem I had on my car about a year ago, and it turned out to be the belt. It would only squeal for a couple seconds when the engine was cold, but it was very loud and annoying. Bought a new belt and replaced it within minutes--very easy to do and the problem went away immediately

 

serpentine belt, opposed to a V belt.

serp = one long belt that connects multiple pulleys... usually ribbed one side, smooth on the other

vs. a old school V-belt, shaped like a V, usually connected to only one or two things max!

 

Dozer if this only happens when its really cold I would lean to it being more starter related. Just did a starter on a MY01 with similar symptoms, which cured the issue entirely. If you really want a proper diagnosis do a walk around on the car with a video camera when the problem is acting up( good audio is important) and upload it on here.

- Hollywood