Yesterday I had a really shocking experience. While tweaking the layout and design of my yet largest project, my network connection seemed to become broken and some tools like PhpED and IE7 (latest Internet Explorer of Microsoft) where unable to connect properly. Well, the culprit was not PhpED at all. Maybe it just hung with IE7 because of its IE7 Debug Plugin or something.
In case of the IE7 this resulted in a crash. I didn't do anything wrong, but after the anti virus software installed on the affected systems recently ran its auto-update, my assumption was the network hooks of it may cause crashing IE7 under certain uncommon circumstances.
I was terribly wrong by continuing with FireFox 3 instead, which came to my mind after other users of the large website contacted me and asked if it'll be up again, soon. The site was unreachable for about an hour for all IE7 users, but they told me it runs fine with FireFox.
My IE7 is configured to open several pages on startup, like big computer news magazines and also my main projects. As soon as the tabs begin to load the pages, all stuff gets loaded. Lots of files are queried and processed, like HTML files, CSS files (containing styles), JS files (JavaScript) and all the images displayed on the pages.
As soon as my own CSS got loaded and IE7 started to process it, the browser completely hang up, needing to be terminated via task manager or time out. Yes in deed, the latest Microsoft web browser of today, in the year 2009, can be killed by style sheets that work best in FireFox 3.
My page redesign focus was to highlight the first letter of a couple of links, so the user recognizes alphabetical order at first glance. It was code like:
.DivClass h2:first-letter{ font-weight:bold; }
That's all it took in my situation to crash the application.
Well I have to qualify this a bit: modern web browsers are really complex applications and with IE8 Microsoft seems to do many things much better than before. On the other hand, FireFox is less secure and stable than most people think. It was secure as long as it was unpopular and so no lucrative target for hackers. As it became more popular, it turned out to have much contact surface for hackers, too.
Enough written about it. Lets forget about it quickly and continue using FireFox and IE7 together to have full control over layout and browser bugs. That's just the agony of coding web applications.