Ok but in this last screen shot your climbing fine. Also there is no wind so for this screen shot did you have any weather defined? If not then weather is most likely the issue.

Is that +13C I see in the first pic? Warm day I suppose.

Try this after take off on your inital climb out don't use VSI. When Lnav is enable and your starting to turn use LVL wing change. Then after about 10,000 arm your vsi works for me . If i try and use VSI on inital climb out in the turns it looses height.

Sorry this is off topic, but Steve, I also got the nose down when engaging vertical speed (I never use this mode but was testing) after takeoff. I havent been able to reproduce it but it happened to me once again when inwas trying to reproduce it, and it happened because I had no active roll mode so the plane went to control wheel steering. Engaging a roll mode (in my case hdg select) turned the complete autopilot on again. And whenever I engage a roll mode before engaging the autopilot with vertical speed after takeoff, the plane behaves appropriately.

The second picture did not seem as bad, but it was still happening, it was just a light flight, so it wasn't as obvious. What should the temperature be for that altitude?

Is the nose going down so it can level off and pick up speed? I see you are 20+ KIAS below what the FMC wants your speed at. This happens to me when I pass 10k ft and the 250 speed restriction is lifted. After it gets up a little steam she noses back up and pours into the climb; however, it never fully stops climbing. It just slows down to around 500 or 600 fpm. Maybe that's what is going on?

Is that +13C I see in the first pic? Warm day I suppose.

Hi Zach, +13C is not a uncommon. The other day I was flying out of OMDB and it was 44C on the tarmac. (Right now they are expecting +17C at FL100) Performed fine. And TAT is always higher than SAT. Colin: Can you just try with FSX clear weather and just a random load with about 8000lbs of fuel. Then it should be able to do atleast FL370. regards,

Hi Zach, +13C is not a uncommon. The other day I was flying out of OMDB and it was 44C on the tarmac. (Right now they are expecting +17C at FL100) Performed fine. And TAT is always higher than SAT. Colin: Can you just try with FSX clear weather and just a random load with about 8000lbs of fuel. Then it should be able to do atleast FL370. regards,

Hence why I said it must have been a warm day.

I actually managed to fix it while flying by adjusting teh weights. Definately an issue I hope for a fix for soon...

I actually managed to fix it while flying by adjusting teh weights.

What were you weights it happened?

I don't know, I just set more weight and fuel, then less.

Edit: It is is still happening NOT SOLVED

We need to eliminate variables. Use the default weight. Again, I am not seeing anything wrong with the last flight. Above the 10K ft restriction, VNAV commanded a lower VS to accelerate to Climb speed and then your back to a normal ascent. What's the problem?

Ok, that last picture was not the right idea. This one shows it well:

Use clear weather, random payload, and 1/3 fuel or so. Then try again. If it's still there, try re installing. Maybe that'll work.

Have you ever waited it out? You are - on both picture - at FL100, aka acceleration height. Also in both pictures, your IAS is below what the FMS has set. Try and let the craft get its speed set properly and then check your climb rate. Edit: Looking over your post, I'm certain that you'll see that everythings fine. When you reach FL100 (or 10 000, if you're under FAA rules), you'll suddenly be allowed to fly more than 250kias. Your FMC sets the optimal climb speed for you when you do the pre-flight. Once the plane's above FL100, and are no longer restricted to stay below a certain speed, it accelerates to the optimum calculated speed setting. Because your engines already are going at full, the aircraft will pitch down for a moment while it gains it speed.