yup problem right now with the wysiwyg editor and internet explorer. Can;t get to the bottom of it yet but I can offer you two alternatives to bypass the problem for now. (2nd is easiest :-)
1. Use a quality browser.
http://www.mozilla.org/products/firefox/ this is far better than internet explorer and actually follows standards, unlike microsofts internet explorer.
2. Go to your profile and select Edit Options - then go to the bottom of the page and choose the Standard Editor instead of the wysiwyg editor.