Maybe this belongs in Server Fault instead, but some of you may have noticed this issue (particularly those developing on Mac, using a Windows machine to read the reference material). I posted the same question on a Microsoft forum and got one answer from someone who reproduced the problem, so it's not just my machine. No solution yet.

Ever since this month's security updates, I find that many web pages cause the CPU to run at maximum for as long as the web page is visible. This happens in both IE7 and IE8 on at least three different computers (two with Windows XP, one with Vista). Here is one of the pages, running on XP with IE 8:

http://learning2code.blogspot.com/2007/11/update-using-subversion-with-xcode-3.html

Here is one that does it in Vista with IE8:

http://developer.apple.com/iphone/library/documentation/Cocoa/Reference/Foundation/Classes/NSString_Class/Reference/NSString.html

You can leave the page open for hours and the CPU is still at high usage. This doesn't happen every time. It is not always reproduceable. Sometimes it is OK the second or third time it loads. In IE7 the high usage is in ieframe.dll, version 7.0.6000.16890. In IE8 the high usage is in iertutil.dll, version 8.0.6001.18806.