Debugged an issue, but why?

corblimey

I got a bug report today that said that some popup menus I had weren't working on IE on a PC. Just IE, natch. After several hours I traced the problem to a comment I'd attached to the php source. It was a simple html comment above the initial <?php. Originally there was a header file above it, but I'd moved things around. The upshot was that the html comment appeared as the very first line in the html source. And this buggered up my popup menus (standard css using li, hover, etc). Great, resolved, but I'm interested in how a html comment on line 1 of the file causes IE to throw a hissy fit with regard to styles. I know IE is a little flaky at the best of times, but is this a known issue?

Giblet

Might it have been a doctype issue?

corblimey

That was my original thought, that it was somehow overwriting the doctype or something, but the page behaving perfectly normally except that it wouldn't show popup menus. An odd thing to choose not to show.

Eoin

Could the page validate with the comment at the top of the page? If not, then all bets are off.