ATC will instruct me to climb to a certain altitude:
"Climb to Flight Level 200"
but then I hear no more. When I realise 'it's that problem again', I check in to ATC, only to hear the pilot say this:
"... out of flight level 200 for flight level 330"
that is then always confirmed by ATC.
No instruction to climb to 33000' had been given (nothing on the onscreen COM log either). If I try to climb to 33000', I am soon told by ATC to maintain flight level 200. I never get an instruction to climb above that (but if I check in again, the same exchange as above is always repeated), so I either stay at that low altitude and mess up my whole VNAV profile (in the FMC) or I just turn PF3 off..
I start my flight in Mode 1 and switch to Mode 2 at or soon after take off. It might be that there is a slight delay in acting on some ATC frequency change instructions occasionally, but I don't think that any reasonable inadvertent delay (and I wasn't aware of any long delays on my part in the current flight - I switched to Mode 2 not that long after takeoff, so any frequency changes should have been automatic) should be allowed to trigger this kind of problem, surely? What happens in the real world if a pilot fails to read back an instruction to change COM frequency? The instruction would be repeated after a short time. In PF3, if there were no reply/confirmation from the pilot to an instruction to change, couldn't there also be a 'nag' after a minute or so (assuming that that is the reason for this error)?
I cut the current flight (as per log attached) short...
Thanks Dave

Martin