not Vista or Windows 7.

The customer reported that our version of Internet Explorer 8 would crash when we visited their website.  We support IE8 on Windows XP.  IE8 was working ok for other websites.  So we fired up a “generic” Windows XP, and it’s IE8 crashed as well.
mshtml.dll error

It’s the customer’s website!

So I fired up Wireshark to see where the crash was happening.  The almost last thing received by the Windows XP PC was this:
Wireshark capture showing JQuery activity

JQuery 1.4 was causing Internet Explorer 8 to crash.  Now we know the cause, we can Google for “JQuery crashing IE8.

The solution:
Well we told the customer to fix their website, by updating their rather old JQuery.

It also turns out that the latest (August 2012) IE8 security patch, MS012-052, resolves this issue as well.  (Update: for our particular customer.  The reference site below still crashes IE8)

Crashing IE8 with two lines of code