I also got the message with a link to http://www.orange-update.com/2
I phoned Orange to check what it was. What a menu system! When I called from my mobile I kept getting cut off, or a message that my call could not be completed at this time. I eventually managed to get through on the freephone number from my landline.
The best menu option that I could fin was for phone faults. I got to speak to someone here, who confirmed that the update was
from Orange, however as far as he knew the only updates being issued were to Nokia N70's.
When I asked him what the update did, he told me that it 'updated the software'!!!
We agreed that as my phone was woring, here was no problem just ignoring the update. That is what I intend to do untill I ind out what it actually changes.