NAV/Radio/I-Drive failed yesterday for 2nd time...

[Tainui]

This is the second time this happened and corrected itself and I'm hoping there isn't a third.
But here are the details:
Upon startup the accept screen comes on, I accepted and the main menu showing comm/NAV/ent/etc comes up.
On the bottom of the screen where you see the radio station - time - date ... all are dashes and it read on bottom left "Acquiring" and that was it. Frozen.

I tried the following a few times in no particular order:
truck off / start up / lock / unlock on the key /

up,up,down,down,b,a,start and nothing.

I drove home 20 miles or so and turned it off in the garage. While digging for the dealer number I decided to try once more and it starts and operated normally.

Anybody have this experience and know of a cause?

(fyi - 2007 BMW X5 4.8, 4200 miles)