sIEve reports DOM leaks for AJAX stuff. In the particular case I was debugging, with a .load() every few seconds replacing the contents of a <div>, unless things are attached to the root document in some way when "freed", they will apparently not be reclaimed until the page is reloaded. IE's memory usage, as seen in Task Manager, reports the same thing (after a few hours, IE will crash).
I pilfered and integrated a fix that seems to resolve this particular problem for me, but as this constitutes my first toe-in-the-water with JavaScript (more like head first into a pool w/o water), I am more than a little wary of unintentional side-effects this change may cause. The extra code should probably be conditional on browser.msie and could possibly be made more efficient (do the innerHtml thing on batches of objects)--and that's assuming that it is the right thing to do in the first place (for IE anyway).
I've seen "discardElement" and similar code in a number of place; I don't recall where I originally got it. I also suspect that the jQuery folks have seen similar code but have chosen not to use it.
I've attached a patch from 1.2.6 to what I'm running. It does seem to solve my problem; I make no further claims...
