Recently, as in the past few days, IE9 in Windows 7 has been exceedingly buggy with the editor, refusing to apply formatting (heading sizes, normal, etc.) when selected from the format dropdown box. There is also an odd glitch where the bottom of the editor will expand downwards after every keystroke. This is happening on multiple computers, both here in our office and on clients' computers at home (I am part of a web design firm). I'm willing to bet this has been occurring after a recent windows update has altered something.
Are you aware of this issue, and if so, is there an update we need to get for the editor?