Yeah, Kurzyk, this is a known feature of IE8, certainly on Elliquiy and apparently on some other forums too though I only experienced it on E. AFAIK your only options are to go back to IE7 or use another browser. There is an 'IE7' compatibility button on IE8 but I had mixed success with it; it fixed some issues but not this particular one of the text and/or cursor sliding about in the post reply window.