Sweet! I talked to Yehuda Katz and let's hold on a little bit more before applying it to see if jQuery Core will release a new version with this IE fix.

That IE workaround didn't actually work for me cause it seemed to target all submits with with a live click intercept.
I used
if (jQuery.browser.msie){
$("form[data-remote]").delegate("input[type='submit'],button[type='submit'],input[name='commit']", 'click', function(e) {
$(this).parents("form[data-remote]").submit();
if(e.preventDefault) e.preventDefault();
});
}

http://dev.jquery.com/ticket/6359 is the most relevant upstream bug.

I just sent a pull request for a fix to this issue. See commit 7d260bc on mpakes/jquery-ujs.

Here's the workaround:

$('form[data-remote]', $.browser.msie ? $('body')[0] : $(document)).live('submit', function(e) { 
    $(this).callRemote();
    e.preventDefault(); 
});

The submit event handler is bound to rather than document, which IE seems to handle just fine.

Matt

This is fixed upstream in jQuery 1.4.3.

Recommending core team to close this ticket.