I have had this message once, under hard acceleration, about a month ago, after owning this vehicle since Sept 2009, and definitely driving her hard on occasion.

2010 X5 M, very early build (first one in Dallas). About 16,000 miles. The message disappeared the next time I turned on, and haven't seen it since. I did not notice any actual power failure.

I have had a multitude of issues with this vehicle though.... it has been in the shop probably for a total of 3 weeks, with all kinds of problems.

But, I figure that is the price of having such a high performance vehicle and a BMW. The quality of German engineering is not quite as good (from a reliability point of view) as the Germans think it is. All my acquaintances who own BMWs tend to agree with me.

I intend to trade in for a 2012 M5 as soon as I can. And I expect major issues with the new M5 too.....