2007 Crossfire Coupe. Have shredded two belts in as many days. Replaced the tensioner today, but it appears that the idler pulley (#4 on the belt diagram) may have seized up.

It will only turn if the bolt holding it in is loosened a bit.

1. What could cause the seize?
2. How do I fix it if it's more than just that pulley?

Thanks guys... this is getting to be an expensive fix....