|Sorry, I missed the fact that you had already done a general registry search.|
Not sure why it should show up anywhere in the registry at all, but admit I've not given this aspect much thought.
Scraping the barrel, try clearing your TIF's & History just in case it is locking onto some previous error.
Crazy I know but you could try going there on Full Security & Privacy (after clearing TIFs). I got there like that, so I was wondering about some cookie issue.
No other ideas, short of running IE Repair if that's what you are using. Kinda rests badly with why OffByOne couldn't get there either.