Sorry but time just ran away with me and I've been playing catch-up with other stuff.
Unfortunately, or fortunately, depending on your viewpoint - I've just gone in and successfully loaded an auction (on 'list similar,') with hardly any problems at all now.
The item description box was there from the start, so I didn't need to use ctnl F5, although typing into the box was a little abstract because if I pressed return the cursor went to the top of the page not the bottom and also the font appeared to change.
Whatever, I got something listed.
But since it wasn't working last time I tried (Friday) have you done something at your end Gazza?
If it helps, when it wasn't working properly it didn't matter where I tried to start an auction from: ie List Similar or List New (I've not had any problems when relisting but then I haven't revised the descriptions either).
I don't have any 'add on's' or toolbars.
I'm on windows XP, IE6, AVG free.
If you need to know anything else, just ask.