Why don't you just take it to the dealer or a local shop and have them check the tightness of it?
I've read that you should have your pulleys roughed up by a wire brush or something of that sort, but you said your belts never squeaked before so that might be out of the question.
BTW: Where can I find the tensioner? Is it the bolt right below the first pulley (Power steering pulley I believe)?
Have you thought about getting your compressor checked? I had a 95 Rodeo with a seized compressor that would squeal.
most aftermarket belts suck, but the goodyear gatorback is pretty good and so is bando (OE supplier for mazda and other japanese makes like toyota)... if you can't find them, then just buy the belts from the dealer
i have gates belts.. no problems
I have done dozens of belts and NEVER had any this tight. I'm scared to go any tighter. Do you guys have your A/C belt abnormally tight?
Yea I think mine might be as well. It's happened on a couple of my cars. Down here we can't live without a/c. Eventually they'll start to lockup and you'll get some squealing. See if you can replace it yourself. I'd imaging it's pretty labor intensive so they might charge you a good amount for the work.