I completely agree on the fuel. Since I got the car 3 weeks ago I have only used BP ultimate, Shell Fuel Save and Shell V power. I am just praying everything will be fine now. Because its a 2008 car but there were only 42,000 miles on it, it could be the fact that the previous owner didn't give it the runs it needed.
I got in touch with the local Jaguar dealer this morning and they said it could be the fact that I was driving too fast when the light had come on. He said that 60MPH is the optimum speed for regenerating and if I was driving too fast it wouldn't of kicked in.
Also, the light was on amber, but still required a forced regen.