I've got some excellent feedback to my problem from forums.debian.net. The problem has taken a turn today and the initial response of filling a bug-report might have been a bug itself. I will try to resolve to issue and keep this bug report up-to-date and see what the real cause is.
The thread at the forum is http://forums.debian.net/viewtopic.php?t=18519 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]