flyingfanatic333 wrote on Jul 14^th, 2009 at 3:41pm:

I actually encounter the same problem. It only happens when REX updates during the descent, and it usually causes the loss of lateral nav (both LNAV and heading select/hold). Yesterday it even caused the 757 to revert to a cold and dark stage.

Yes got the same as said, only when rex updates (after 1 hour 1/2 )
as well with the 767.
With other add-on (aircrafts) I have no problems.