This was a common problem with the older (smaller) idler pulley. It happened on mine (seized up), shredded the belt and I had to get towed.
Contact Vortech about it, it is a known design flaw and they will ship you a new bracket with a *much* improved idler pulley for free under the warranty. Besides a strengthened pulley design, a side benefit is you'll get a better wrap on the blower drive pulley which translates to less slippage/more boost (and yes, the larger idler means it is more difficult to install the belt).
You will have to provide a credit card number if you want the replacement bracket/pulley shipped in advance of the return, but they will refund the $240.00 something dollars when they receive your old bracket back. Good upgrade.