Never ignore a bug you don't understand.A bug you don't understand is an opportunity to turn code you don't understand into code that you do understand. In particular, the next swing you get at this bug might be in a much uglier situation that's much harder to reproduce or diagnose.
So better to at least do the diagnostic part of the bug fix immediately. You never know: maybe what you thought was cosmetic and trivial was a symptom of something much worse.
Once you understand the bug completely, then you can say "let's not fix this just now."