strange midi bug

last night I experienced a very strange issue. I use BFD2 for the drums. I was mixing and everything was working fine. Then I noticed one particular drum stopped working. All of the other drums were fine. I reloaded the drum sample, still didn't work. closed and reopened the project still didn't work. rebooted still didn't work. Opened a previous version of the same project and it worked just fine.  Went back to the project with the issue and deleted the midi notes and "re-drew" them back in, still didn't work. added a drum to BFD2 and moved the midi notes to the new drum(same sample) and it worked again. I looked at the event list and didn't see anything abnormal.  So it seems this is not a BFD2 issue. Almost like there is some corruption just on that one drum's midi notes. BTW I looked at all of the mix settings for that drum in BFD2 and it should be working. spent a lot of time trying to troubleshoot, way to much to list.
 
anyone have any ideas about this?

when I playback the project, the drums (midi) plays normally as it should with the exception of just the one sample, up until then everything played back just fine with no issues.  The velocity is fine, none of the other items you mentioned are an issue.

imagine you programmed a drumbeat. You hear the hihat, kick, cymbals but you can't hear the snare.  you see there is a triggers for the snare, everything you see indicates you should be hearing a snare, but you don't. so you insert another drum into BFD2 and you assign that new drum sound to be a snare and move the midi notes to the new line in piano roll view and now you hear the snare. 

that is exactly what I did as mentioned above. It is definatly a sonar issue, i suspect somehow there is a "curruption" (lack of a better term) in the midi data storage in the project.  I have been recording several songs and for consitency I use the same "drumset" on all recordings. So all projects are using the same samples and settings. Everything is pretty much identical. No other project has any issues, just the one project. So I am pretty sure its not BFD. and since I inserted the same sample into another slot and it works now, makes me think there is an issue with Sonar.
 
So for now, I am pretty much done with the song/project and the work around is fine. But I am mostly curious and annoyed with this issue. it did side track me for an hour. I mostly worry it could happen again and be much worse of an issue without a work around in the future.  If you have BFD2, I could upload the project file without any audio tracks (just the midi drums) and you could see for yourself the behavior. Maybe I am missing something you might see right away.  It has dumbfounded me!  :)

Did you try this?

Perhaps try even higher, just to see if it sorts the problem for this one project.