Dodge Caravan - squeals when starting in cold weather.

My mom has a Dodge Caravan, I think its a 2000 and has 120k miles on it.

lately shes been having belt troubles with it. The serpentine belt went and so did the power stearing belt. Both were replaced by a mechanic.

now, it sounds like another belt is going. When starting the van in cold weather, thiers a loud squeal that sounds like a slipping belt. It usually almost goes away when the engine warms up. We have takin it to 2 different mechanics and they could find nothing wrong with it. It diden't squeal at all for them when starting it.

is thier anything else that can cause a squeal when starting that sometimes goes away when the engine is warm?