It turns out, the newest Nvidia Geforce graphics card drivers in OS X 10.8.2 are causing the issue, and Pixelmator is working with Apple to resolve the issue.
The affected Macs have GT 120, GT 320M, GT 330M, 9400M, and GT 9600 Nvidia graphics cards.Everything we do at Pixelmator Team is aimed at making your favorite app the best in the world. With every minor update, we strive to live up to a high-quality standard. We even put aside new features, such as layer styles, for the sake of quality improvements. So far, we are happy with what we've achieved. However, there is one issue we wanted to talk about a little bit more.
A month or so ago, after the most recent OS X update (10.8.2), we've bumped into a problem that causes certain Macs to restart when intensively using Pixelmator. Sometimes, the app would stop responding without restarting a computer, or just cause some graphical glitches.
We did everything to find the root cause of the problem. We've researched a vast amount of information about OS X internals. We've torn down our Macs. We even reached out to Apple. Finally, the picture was clear: It's an issue with Nvidia Geforce graphics card drivers.
Although the issue isn't with Pixelmator, we didn't give up. We've searched for various workarounds, and then, we checked with you to see if any of them helped (thanks so much for being so patient and for taking the time to test those workarounds). But in the end, nothing worked.
Good thing, though--the guys at Apple are very helpful, and as soon as we hear about a solution, we'll let you know about it that very moment.
Article Link: Pixelmator Apologizes for Crashes Resulting from Nvidia Driver Bug