Shortly after posting this I've managed to find the answer!

It's at this link if anyone is interested:

http://social.msdn.microsoft.com/Forums/en-US/sqldatabaseengine/thread/1a72b36e-628b-42b5-85fa-c53fe6825c3e/

Thanks Bhuvnesh, but I've already read this resolution at

http://blogs.msdn.com/b/sql_protocols/archive/2006/02/21/536201.aspx

I've also previously read the feed from http://www.sqlservercentral.com/Forums/Topic570042-5-1.aspx#bm571110

but I've tried everything suggested in these posts.

The sql account has permissions to...