Nonreproducible bugs

Wheee, fun at work today. Part of my job involves developing and maintaining the backend for my company's website. We put out a new release of the main product last week, which involved also putting out a new version of the website backend.

Since we're at least moderately sensible here, we have a pretty thorough testing system, and everything passed (or was deemed minor enough to allow through) for the release. All well and good.

Today I get in to the office and there are a bunch of emails from the boss, who is out of town at a conference, promoting the new version and telling everyone to go download demos. Apparently, many people are having problems downloading our demo. Error messages about bad email addresses, can't access the download page, real obvious stuff. Stuff the test cases should have caught.

Actually, the test cases really should have caught the problem. But even now, I've spent all day trying to reproduce the bug, and everything still is working fine. I've tried all sorts of weird situations to try and get the page to fail, and it hasn't.

I'm now at the point where I just put in a bunch of logging code, uploaded a temporary version, and now I'm sitting around waiting for someone else to try to download a demo to see if they have problems.