HI Adam
I have just created a fudge to get this working on our locked down IE5.5.
Basically when the page first loads, the toolbar does not show and neither does the HTMl. I have added a button on the form when it detects IE5.5 which the user can click to goto another webpage which then uses history.back() to go back to the editor page. Amazingly the toolbar and HTML are now there!
There are the odd javascript errors on some of the popups but we had those on the 5.3 version of your editor. So our users are used to those ones. The menus have a strange [[ ]] round every time, too but can live with that. The main thing is that they can edit the html in both views and save etc.
You dont seem to have spotted this item at all. Fix that and I should be able to finally upgrade.
Cheers