Sonar LE 8.5 - Piano Roll - Some notes play, some dont, entered the exact same way.

I imported a midi track of a file i made in guitar pro. I had to edit it a bit because it didnt sound the way i wanted it to. Basically theres a long bass line that sounds exactly the same, and at some parts it cuts out for no goood reason, everything is the same. I have attached a picture of what is going on so you can see nothing is input wrong its just not playing at certain parts. javascript:EditorPasteHtml('') Any help on this would be appreciated. Also, any idea why when i hit the playback button, sonar decides to play what it wants when it wants? Meaning, sometimes certain drum parts will play, and then it wont, then itll come back or a bass will miss out. Its making it impossible to record guitar over it when it keeps cutting out. When the file is exported into a .wav file it sounds fine, other than the problem i described above. Any help on this would be appreciated.

Hi Greg, thanks! Glad to be here.  To answer your questions. What operating system are you using? Windows 7 Home Edition How much memory does the computer have? 8gb RAM What sound card or audio interface are you using? Audio Interface is Line6 Toneport UX2 Under Options>Audio, what is listed for I/O Buffers and Buffers in Playback Queue? Im assuming I/O means Input and Output under the Drivers Tab, so it says for Input Digital Audio Interface (Line 6 Toneport UX2) and the output says Speakers (Line6 Toneport UX2) The playback queue im assuming is playback timing master and its listed as Speakers (Line6 Toneport UX2) same thing for record timing master. What is the listed Latency? Latency im assuming is under Mixing Latency and it says Effective Latency at 44kHz stereo: 300.0 msec What synth are you using to hear the MIDI? Im using Komplete 8 Ultimates Reaktor 5. Thanks for you time Greg

  Changed to ASIO mode, it fixed the issue i had with the notes deciding when they want to play. But the first issue is still present. Heres a picture of my piano roll so you can see what im lookin at. It has been boggling my mind for weeks now and i have to get this song finished in 2 weeks and this is my only issue so far. Other than one i just stumbled accross and it has to do with guitar rig only playing raw guitar sounds into sonar under an audio track. Theres no effects or distortion like i hear on playback. If you know something about this i would also appreciate your help with that to. :D Thanks again Greg.

Put the Input Echo on to hear FX when you record.

The resolution of the picture of your MIDI track doesn't show if there's a long sustained note or the same note picked repeatedly.
If the latter: The most commion reason for randomly missing MIDI notes is too low setting in "MIDI buffers...prepare using."

I don't have that synth so I can't try it out to see if I get the same behavior.
Change the buffers as Kalle wrote and see if you get better results. Regardless of whether the notes play fine elsewhere, there could be more stuff going on here that might put the processor or synth under greater load.
If you bounce the synth to audio, will it play the notes?
You might try decreasing the duration of the note leading into the other, non-heard note.
As a last resort, you can put the missing note on another track played through the same synth, if the bounced track also doesn't let you hear the note.

Does the synth have a control that allows you to increase the polyphony (how many notes it will play at the same time)?

In you PRV picture, it looks like the end of the first note is "butted" right up against the start of the second note. Drag the end of the first one back a few ticks and see if this helps.