Just had this reply from Apple......
Dear David,
I've been contacted by our engineering team, that the upgrading issue should have been resolved now. Therefore I would like you to try again to upgrade your account to a a family pack.
If it still fails, please let me know, and I will forward it to our engineering team.
If you have any further questions, please let me know.
Yours sincerely
Lars
MobileMe Support
Apple Operations Europe
Tried it again...... Please try later.... 🙁 Oh and a pre-authorisation on my card 😡