MIDI pitch change

Playing back a certain project, if I start mid-stream at certain points a MIDI track is changing pitch upward by one full step (2 semitones).  If I go further back in the project and start play, then it plays properly. It is only at a few points in the project this occurs.  The notes are mapped out properly -- I've checked them in Event List and Note Properties in PRV.  There are no other notes showing on the midi channel that might be acting as a trigger, other than the desired note.
 
This is a midi channel going to bass synth (Guitar Rig Skobee PreBass), then to my bass instrument track.  Never had this happen, baffled as to what's triggering the pitch change.  I don't think my input keyboard could be affecting this, but the pitch wheel is physically centered; and no controllers are showing for the pitch wheel in this section of the track.

Check your Event List for any extraneous CC's

Any pitch markers inserted on the project?

I cannot find anything in the event list that looks inappropriate, nothing outside of the notes being played .  Swamptooth, your link / comment is exactly what I thought at first -- perhaps I had re-tuned the synth so it was modulating upward, but it was still set to standard tune.  The link indicates a problem with playing incorrect notes after modulating to an alternate tuning, which I am not doing -- but I thought perhaps it was a bug in the Native Instruments software.  So I replaced the synth with SI Bass.  At first it played OK, so I thought that solved it.  I reloaded the NI Skarbee bass and verified the same problem.  THen I reloaded the SI Bass, but this time it occurred with SI bass too, so it seems to be something in the midi.

I checked pitch on the keyboard and it seems to be OK, it is what is playing that gets off.

Again, what seems weird -- if I stop the song before vs 2 or the bridge, then resume play from that point, THAT is when it occurs.  If I play from the beginning of the track, it does not change pitch.

Baffled.  And frustrated!

try running the midi filter on it and stripping everything but notes. insert a second audio track with input from the synth so you can a/b compare them.  then try inserting a whole new instance of the synth with the midi line and a/b that with the original.

does scarbee have an lfo that's going on??  is there an lfo or autowah or psyche delay in your guitar rig setup??? those might be sync'd to cause pitch changes.  

LOL! 666!!!

@BJ
One of the key things with keyswitches is to have separate midi tracks that represent the various switches for the sake of consistent playback as well as notation printing.  The other thing i do is add a meter change at the start of the file - set to either 1/8 or 1/4 and leave that for a bar to assign the initial keyswitches then change the meter to first assigned to the project.  

You guys are geniuses!  Went back through with all you'd noted, found a few previous floating pitch bends that had not been zero'd back out.  So I guess it had floated off from there.  I put a zero pitch bend controller in after each of the offending events, and it seems to have fixed it.

What I don't understand -- prior to correcting this, when I closed the project then re-opened it, moved NOW time to mid-project and started from one of the mid-track points without passing any pitch bend, I was still getting the errant pitch.  Shouldn't it have started playing at that point without acknowledging a pitch bend prior in the midi track that it had not actually played?  Or does the audio engine look retrospectively and play as if everything prior had actually been played?

Thanks for the help!!

swamptooth


@BJ
One of the key things with keyswitches is to have separate midi tracks that represent the various switches for the sake of consistent playback as well as notation printing.  The other thing i do is add a meter change at the start of the file - set to either 1/8 or 1/4 and leave that for a bar to assign the initial keyswitches then change the meter to first assigned to the project.  

swamp - yep, all my keyswitch data is actually contained within a drum map which lives on the top row of the PRV. The 2nd row is for normal note data, 3rd row for velocity & 4th row for CC11 data

Yeah and the cool thing about drum maps is that one big map can go to multiple synths which is awesome!