As I try to write more and more complicated applications myself I have become a lot more tolerant of bugs in other peoples software. And this especially true when the bug seems random because I am learning myself just how hard those types are to track down.
I've got bugs that aren't *MY* bugs, but they affect my software. There's a serious bug that is in an audio driver that affects me. Not good. It's rare, so I won't fix it. (Sometimes you have to sacrifice.)
I've also got other bugs that are totally my own fault. They'll get fixed.
Another class I find are "environment" bugs (I use the term very loosely there). These can range from simple to find to impossible to locate. I recently was able to reproduce a bug, but I can't precisely define the real problem. Not fun. I'll have to hack around some BS to fix it most likely, which I don't like. I prefer to have straight forward, simple and easy code that is clear.