I received my call earlier this afternoon and spoke to several people all of whom spoke English (with various accents).
The guy who rang me yesterday was the first. After "consulting with his seniors" they had decided that - after he has been responsible for the case for over a week - it is nothing to do with the Vista team that he is part of because it is a problem with IE8 (which is what I have always told them, in writing

).
Because it was nothing to do with his team he wanted to close the case (even though it hadn't been resolved) but I insisted on being transferred to the IE8 team. In the event I was actually put through to someone in the Developer Support team who, after several minutes, decided that IE8 problems were nothing to do with him.
I was then put through to the IE8 team - but not the technical team, just the one that helps you if you can't even install it. After several minutes he decided that he couldn't help either and wanted to put me through to the original guy again - but when I convinced him that doing so would be no good he finally put me through to someone whose job is actually to allocate problems to appropriate teams. She has taken my details and will, hopefully, be able to escalate the problem to somebody with the appropriate technical knowledge.
Over the total of 78 minutes and 48 seconds (thank goodness, once again, that Microsoft were paying) I lost count of the number of people I spoke to - people who dealt with the transfers as well as the ones mentioned above. All were very polite but, until the last one, seemd to be in their own little boxes with no knowledge of what goes on in the rest of Microsoft.
Circumstances mean that I won't be able to devote much time to the problem over the next few days so I can but hope for a solution to be found using e-mails only.
Watch this space

Graham