First, this is general coworker issues, not issues with QA people in general. QA people aren't a special subspecies of Homo Sapiens. They shit, shower, and shave, just like you.

A few points, in no particular order.

• You are uncomfortable with one of your work partners. This needs to be brought to your boss's attention, if for no other reason than it is making you uncomfortable. I am of the opinion that your boss exists to make your worklife easier, so that you can get your job done. If something might impede that, it's his job to make the impediment go away, whatever that means.
• Have you tried taking the guy out to lunch and just asking him "Hey, I feel you might be treating me differently than the other guys. Is there something I can do to make you feel more comfortable with me?" Always frame it as "What can I do to help you?". Don't attack him; all that does is make him defensive and that leads to one thing - a fight.
• Don't make mistakes. Maybe, this means you have to ask the QA guy "Hey, would you mind explaining to me where I'm going wrong so I don't make the same mistake again?" Maybe, this means you spend more time unit-testing and building a testsuite of your own, so you can at least document what you tried to test on your own.
• If all else fails, go talk to HR.