Costco in South Austin Selling Heat-Damaged Wines?

So in May of 2006, a new Costco opened here in South Austin. I had previously bought some wine from the North Austin location, and all without incident. When the new location opened, I bought a few wines (4 or 5) in June and all were heat damaged (stewed, vinegary smells and flavors). I wrote this off to summer heat and improper handling practices and vowed not to buy more wine until the weather got cooler.

Fast forward to today...I purchased a bottle of 2001 Colombaio Casisano Brunello di Montalcino off the shelf (they've had it for weeks) for a very reasonable price tag of $30/bottle. When I got home and tasted it, it is once again cooked...

I am now beginning to wonder how this keeps happening despite the fact that it has not been hot enough when the wines came in for them to get heat damaged. Are they buying heat damaged wines and sell them inexpensively? I have brought this issue up before, but this time, I will ask to speak to their wine buyer to voice my concern to him. I have bought 5 different wines in a 9 month time span and all have been heat damaged. I can no longer believe this is a coincidence.

Anyone else with similar experience (whether with Costco or another retailer)?