Have a problem with the 747 at cruise.Speed keeps increasing. Everything looks ok and I don't know why it's doing it.To fix the problem, I have to disconnect the autothrottle, reduce power to idle, then re engage the autothrottle.Any ideas?Goran

Heres a couple specific bits of further information that might help: 1) Just above the PFD's airspeed tape, there is a magenta number. This is your target airspeed. Are you going faster or slower than this number? 2) Next, across the top of PFD are the FMAs. What is in the left (thrust) and right (pitch) FMAs?3) Next, what is the thrust level (N1) just before you disconnect the AT?4) Next, after you disco the AT and reduce thrust to idle, then reengage the AT, what does the left FMA say and where does thrust go?

i'll do a flight and post details and a screenshotGoran