fatal IE css bug

Using the RC1 grid in Windows XP SP2, IE6. Sometimes (not always - depends on the page) the grid dies when calling grid.refresh(). The problem appears to be with css expressions requiring "this.parentElement" - sometimes this resolves to null, and the css interpreter goes into an infinite loop. I was able to bypass the error by altering panels/grid.js, panels/horizontal.js and scroll/bars.js to replace any css expression of the form

expression(this.parentElement.client ... )

with

expression(this.parentElement?this.parentElement.client ... : 100)

Obviously I don't want everything to resolve to width/height of 100, but I didn't know the proper expression to put in there. Is there another expression I can use that does not require "this.parentElement"?

-bump- :)