Hi Patrick,
Thanks for sharing your concerns. The QA process is a bit like being the goal keeper in a football game (ok, soccer if you insist). You're never remembered for the dozens of saves you make, you're only remembered for the ones you let in.
We have developed a robust development process where every single commit we make is peer reviewed before being committed into our repository. We then test it on a private staging site, and then we release betas for a few weeks before releasing the final version.
Unfortunately, a few things have slipped through and these have been fairly complex issues which are difficult to test with a small group. Fortunately, we do have a patch system that allows us to get fixes to you almost instantly via the AdminCP.
We always review internally when things go wrong, and we will do based on the information you've provided.