Since SP1, I'm randomly losing the green illumination of the LNAV button in flight. LNAV itself does not seem to disengage since it continues to be announced on the PFD and the aircraft continues to follow the given route.Turning LNAV off and back on brings back the green illumination.Didn't have that issue pre-SP1.Any thoughts?

Hi Dave, I'd hate to make a post without having a suggestion but I have a very similar problem and made a post earlier here.http://forum.avsim.net/topic/353202-possible-post-sp1-bug/I just wanted to give you the link in case something resolveful is posted on my thread, I will be checking here often for the same.Devin Mack

This and other weird things happened to me, too. I did an installation form scrath with Win7 , FSX and the new base installer with SP1 included , and everything works perfectly, now.Regards.Miquel Egea.