Everyone has visited a site from time to time that will annoyingly change the size of your browser. There's a quick solution to this problem. Copy the following code and save it as a bookmark. You can adjust the width and height by editing the two numbers you see. The next time you stumble on one of those sites, just click on your new bookmarklet. It works on every browser I've tried, but I'll bet there's some version of IE it doesn't work on.
Alternatively, you can just drag this to your bookmark bar. If you want to see what it does, just click it.