This was due to jQuery bugs #2614 and #3880 – there were definite problems with the ready code in IE in 1.2.6 and in 1.3 – and now a different set of problems in 1.3.1.
A larger discussion can be found here:
http://groups.google.com/group/jquery-dev/browse_thread/thread/3abf45d3fd4d50fc
And the ticket related to the issue can be found here (if you find additional issues with the fix, please re-open the ticket and post to the above jquery-dev thread):
http://dev.jquery.com/ticket/3988
I just landed a fix for this in SVN rev 6170.
I just pushed up a new nightly that you can use until 1.3.2 final comes out:
http://code.jquery.com/nightlies/jquery-2009-01-28.js
Sorry in the delay for getting a fix out – was traveling this week.
There are some things that just can’t be unit tested. Just confirmed in IE6+7 and 1.3.1. Holy hell, what a huge regression.
So, do you have time to report this? Just checked and it’s not a known bug for 1.3.1.