Hallo again.
 
My problem is caused by the plugs and solved with freezing the tracks with LP64 EQ and PS, or increasing MIDI buffer to 500.
 
It is always the same notes that are missing from the loops when it occurs, as you experience.  One might expect it to be random, but it is always the same bits of the kit in EZDrummer that drop out.  HH and snare, in my case.  Just thought I'd pass it on.
 
Hop you solve this.  Steve Jordan is a fantastic drummer, he really grooves.  If you've got close to his feel they must sound great.

Well, I've experienced this and to me it was all about discovering a new thing about Sonar and MIDI.

It may not be the case but give it a go.

Right click on a MIDI note that doesn't make any sound. There should be a box saying "Channel" and this might say something entirely different than "1". If it does, then this is most likely why you don't hear any sound when it triggers. When you record MIDI, the MIDI chanel on your controler is apparently inserted into the note data and will playback that particular note on channel 2 - or whatever it's set to. Some VSTs will play back that note on a different channel than what the loaded instrument is geting it's input from. This way you can load one patch for kick and snare (channel 1). one patch for hats and toms (channel 2) and the last one for cymbals (channel 3) in Kontakt for example, and just use one MIDI track to control the three different channels. However, I believe this doesn't apply to Session Drummer so it just play back all the MIDI that is sent to it. I think it's a bit of old school MIDI. IDK.

so check the silent notes to see that they are sending to channel one (or whatever channel the notes you can hear) and you should be able to play back all the notes.

You can highlight all the silent notes and change the channel in the Event Inspector if I recall correctly.

I hope this helps.

ProjectM!!!  

You deserve a beer on me.  I wish we were closer, I'd personally deliver your favorite choice of alcoholic beverage. :)  

That was the issue.  Apparently somehow, and I do not know how, these notes in question, had their channel changed to 10 and it should be on 1.  Like you mentioned, I'm always discovering a new thing about Sonar and it's deeper level of midi workings.  Many times, due to my quick keyboard short cuts, I might hit the wrong shortcut, not aware of what I might have implemented.  I've had the great pleasure of being in the presence of some top notch music producers and watching them work with their quick macros and shortcuts is amazing.  It's such a time saver and helps the momentum of my workflow, Until!!>>>>>  "I have to discover some new deeper workings".  LOL  

Thank you all so very much for participating and contributing with your thoughts and ideas.  I hope this was the solution for some you who were experiencing the same problems.  I'll be sure to PM you to read ProjectM's post.  

Mix it like it's Magic!! 

Best wishes to you all.  

Hey Curtsong, I am very happy to hear that and I am glad to be of assistance. Have fun with the new discovery and I hope it goes well from here

BTW - If I make it over to Florida some day, I might get in touch with you about that beer

  Do you have any midi fx on the clips? eg. midi Quantize? Even with midi buffers at 1000, with midi quantize plugged into a midi clip or bin I have random midi notes drop out as well. Have for several versions now. I add a layer to the track, ctrl/shft drag to copy the midi clip with effect to another later, mute the original with quantize still inserted, then bounce to clip the clone. I save the original encase I want to make it swing more, or make it less perfect. :)

Also, In Kontakt where it says Midi Ch: (A)1, you can change that to OMNI. Then Kontakt will see all channels. Seeing as how your problem was midi channel related. This is where you tell Kontakt what channels from Sonar (Host) go to what instruments in Kontakt.

No midi EFX, Blogman. Got is resolved.  

Wasn't able to change all the selected notes in PRV and edit their channel properties at the same time.  Discovered through further search the best way to change multiple events is through:  Process / Find/Change  Then select only Note and find all notes that were assigned to channel 10 and replace them with channel 1.  

That was the most efficient way to edit them.  

Wow!!  What a learning experience.  :)

Saw that after I posted the first time. You can however switch that instance of studio drummer to omni as I suggested instead of having to manually hunt down and change each notes midi channels. Multiple ways to skin cats.

There is an even easier way to change all notes on a track(s) to a single channel. Select the clip and then use the event inspector in the Control Bar. Simply change the channel there.

The event inspector is often overlooked for midi event changing operations but it's the quickest and easiest way I know of.

I also recently pulled up some older legacy files for Sonar 8 into my X1D and had to use this technique on them in order for the tracks to play in the current version.  

Good to know.