Now, I want to be crystal clear here, I very much respect the job profession of Quality Assurance (QA's). I think, without having a QA watching your back, you are screwed. And if you are lucky enough to have a QA watching out for you, it is in your best interest to be respectful and appreciative to him or her. I have seen too many developers make fun or tease QA, and guess what happens, they test someone else's code, and you leave out to dry. Don't be stupid, respect your QA.
However, QA's do have less expectations placed on them. They are not required to know half a dozen programming languages, design systems, debug software nor are they having to coordinate their efforts with other programmers.
Their job is to assure the quality of the system, and to verify it is working correctly.
I think it is of the upmost important, that we, as IT professionals understand that QA's and Dev's are two sides of the same coin. We fundamentally want different things, and that is perfectly fine.
To the developer reading this, I want to say. It might feel like your QA is calling you out, and making you look bad by pointing out your mistakes, but understand he or she is watching out for you. QA is responsible for making sure your software is bug free, the faster they find them, the sooner both of you can move on. Debugging issues in production sucks. Don't be a dick.
To the QA reading this. Part of your job is telling programmers they are wrong, and their code doesn't work correctly. Now, that being said, there isn't a person on the planet who enjoys knowing there are flaws in something they have built. If a developer seems to gets irritated with you, maybe try to understand it's really an insecurity. If a developer ignores you, they might just be busy, but you need to make sure he or she understands the issue you discovered, and he will probably tell you are wrong, and you aren't. You have to stick to your guns, and make he or she understand, because it is your job.
And to Anyone else reading this. If you hear a developer call a QA stupid, or even if you hear a developer make a "light-hearted joke". I encourage you to take it seriously, it may look innocent, but it isn't. You need to step in, call the developer out, and mention that the QA is doing their job, and it is not the developers job to question the accurately of the quality assurance specialist.