A couple of points...
Firstly,TeeCee - apparently, pressing the brakes won't switch off the cruise control in the error state, or at least, not according to my reading of the 4 letters I have from Jag so far... And the CC on the x is different to the mondeo - it's more like you describe the GM one - up/set, down, resume, cancel, but no on/off like the mondeo has.
Secondly, Im told by a ford master technician that it's similar to a problem with the ranger they had a couple of years ago - recycled code that someone has just noticed, perhaps?
Thirdly, this has been out a while, as I got one of mine done, but then Jag suspended it as it had a nasty habit of frying ECUs, and I haven't been told that it's been restarted again cos I'm still waiting for the other one to be done.
Finally, most importantly, so listen up El Reg, it's not just 2006 to 2010 cars - there are some '55 plates affected, including mine. Bugger.