This is the third time I write in here, hoping to get some answers.. When cruising in the NG

If you're referring to periodic slight wing up-down movement, I get that with all FSim aircraft when flying with the autopilot, specially when following an LNAV flight plan, not just the PMDG 737NGs.Best regards from KMIA,Kerke

It's a product of the LNAV algorithum (I think?? PMDG correct me here if I'm wrong.)FS default aircraft (or any *not so complex* aircraft as the NG) follow the autopilot from point "A" to point "B". In the NG, it seems that the auotpilot actually follows the "line" drawn between point "A" and "B". What you are experiencing is the corrections of the aircraft as the FMC attempts to follow a path, not point-to-point.(I know that sounded a little convoluted. If it doesn't make sense, ask me and I'll attempt to clarify)

Ok guys. Thanx for that, somewhat clearness brought to the matter.. ;-)Sort of "glad" that others also experience this..