That's normal for Internet Explorer. I get the same errors on IE for Windows. I'm not exactly sure why it does that, but it does. You can try disabling IE's Javascript feature by going into the preferences.

My recommendation: Unless you're absolutely attached to IE, try Apple's built in browser, Safari 2.0. Or, if you're feeling adventerous, download a copy of Mozilla's Firefox. These browsers shouldn't give you these problems.

IE is a deprecated browser on the Mac and is woefully out of date (it's not had any additional coding changes since 2003). It's no longer distributed by Microsoft for use. As noted previously you should really move onto another browser, such as Safari, Firefox, Camino, Opera, or the like.