Squealing fan belt?
 

Have you ever had any problems with a squealing fan belt? Whenever it gets cold or damp when I start my car first thing the belt sometimes (not always) briefly squeals, then it's fine. In the summer or when it's hot it's fine, only happens when it's cold. (also happened when I put lights, heater and demister on) 60 seconds after the car has been running it's fine. I've had a new fan belt, power steering belt and a new battery, but it still does it when it's cold. Have you had this happen?

Like I said it only happens in cold weather, so could it simply be that the belt is cold and needs to warm up? This doesn't affect the performance of the car, it's just annoying! My mechanic has said it doesn't need tightening as if you over tighten the belt it can damage the alternator? he seems to think it's the change in temperature that causes it. Just wondering if anyone else has come across this?