It appears the new profile pages and the use of jQuery 1.5.2 combined with IE8 (on Win7 here) are running into this bug which appears to have been fixed in later versions (1.6 and above).
The new profile page loads fine, but when clicking on most of the other links on the page, it throws a
'type' is null or not an object jquery.min.js, line 16 character 26101
I don't really expect a fix to this any time soon as upgrading to 1.6 and beyond has other implications, just pointing it out.