Hi all.I got two big problems after 747 update.1. Take off climb rate is very very slow after engaging LNAV and VNAV at about 1000 feet.2. If I climb to cruizing altitude (i.e. FL300), after a few minutes speed slowely drops below set speed and engines don't kick in to catch up to set speed again. LNAV and VNAV are still active. Eventually speed drops until I get stall and nose pitches up like crazy and cant get her back down. Also get stick shake sound very very loud.Can anyone tell me where I am going wrong?This never happened before update.RegardsAnthony ReesCape Town (FACT)South Africa

Whats your takeoff weight?

Anthony,It seems others are also having problems with VNAV at cruise post update, me included. Do a search with "VNAV" and some posts might help you out.