I'm flying an Avro RJ85 from KBOS to KBTV at assigned 18,000.Altimeter is set correctly but the controller tells me I'm "700 feet below assigned altitude, climb/maintain 18,000." I even dropped to 17,300 to see if that helped. No luck.First time this has happened.Any clues appreciated?JimVT

Define what you mean by "set correctly".

Jim, was this with the FS9 ATC or online such as Vatsim? I once made the mistake of filing for 18000 ft and used the FS9 ATC. What happened was that it couldn

god dag och tack sj

I should have mentioned this was FS9.The altimeter reading given me was 29.91 and my altimeter was set at that barometric setting

At 18000 and above, the altimeter needs to be set at 29.92, not the local altimeter. Avoid FL180 since the ATC can get confused about what altitude you should be at from you being right at that transition altitude.

Right...I forgot about the high level setting.Thanks