Hello Adam,
When I compare the demo's of the new CE 6.0 (congratulations with the release!) in IE7 and FF2.00.3, I see some differences (FF shows small icons on the table's cell borders for inserting rows and columns, IE7 doesn't show these). But I assume that the IE7 version will soon also support this handy functionality.
Another thing is that when I place the Text Cursor (I-beam) in a line of text of the Cute Editor demo, the last word of the line is being wrapped to the next line. This also results in a vertical and horizontal scroll bar that are being displayed. It makes the appearance of the Cute Editor very nervous. But when I open the demo in IE7, it all looks very stable and solid.
Since this is only cosmetic and not blocking functionality, I think it still can have impact on how (new) users experience their (first) impression of CuteEditor.