Glad someone has brought this subject up. I have always meant to, but never quite got round to it!
I fly the 737NG and have found the A/P on to be a tad troublesome at times.
I've had 2 incidents recently that both went something like this; with the A/P recently engaged at N1 after t/o I had selected LVL CHG to climb the a/c at 250kts, to bypass the altitude restrictions in the FMC, as we had been cleared to a FL above the highest restriction on the SID by ATC. The A/P then had a brainstorm, having achieved 250kts it pulled the nose up quite normally but failed to stop at a NU pitch attitude appropriate to the speed, let the speed wash off alarmingly quickly and hit a maximum ROC of 6500fpm. I disengaged the A/P and brought it back under control, then re-engaged everything and the flight continued quite normally.
This then happened again the next day, in the same circumstances as before. Both incidents were reported in the tech log. Still have no idea why it happened though, didn't get any feedback at the time.
Anybody have any thoughts?