This has only been reported by Mac users. There may be an OSX version problem/incompatibility with the binaries we're building. We avoid this problem in Linux and its many versions and distributions by not distributing PixyMon in binary form.
If PixyMon is crashing, we'd like you to send us a note (support@pixycam.com) so we know which OSX versions need more testing/work, and we'd also like you to try to build PixyMon on your machine. It's easy, and it's likely to fix the crashing problem. And if it doesn't, let us know!