[Solved] Continual midi note dropouts issue

Hi Folks, I have a strange problem where midi notes are not played. Regardless of what file I play or if I use a pattern sequencer from a drum machine the result is the same, in every bar random notes are not played.
The issue seems to be a disconnect between whatever is transmitting the midi note command from the source to the output within Sonar. I can see the the meters on the instrument playing the note indicating that a note has been played but it does not reach the input device.
The problem is easily replicated by something as simple as setting up a single midi track with four closed hat events and looping it.
Here are a few facts to set the environment:
1) The machine that I am using is a Dell Laptop Latitude E6430 CORE i7 vPro with 8G of ram and everything that I can possibly stop running stopped. CPU load on both the local indicators and the task manager indicate that the CPU is only running at about 20%.
Software is Sonar X1 Version 21.5.00 Build 32 Foxboro - x64
2) The problem occurs with both internal synth instruments and external hard-wired midi instruments such as a drum machine. This should infer that the problem is not audio related.
3) When I edit a midi file, save it and play it on another device such as an iPad, it works perfectly. This should indicate that there is not a problem with the midi file and I can confirm that I can see every note in the event list.
 
I am an engineer/programmer by profession and a muso of 30 years and come from the days of loading tape files onto an Ensoniqe ESQ1 live on stage, to running a Fractal guitar rig for the last two years, so have a reasonable expectation of how these things should work :-)
 
I realize that this is a difficult issue to try to solve without access to the machine but I have been struggling with this issue for months. I have read hundreds of pages of info to no avail and am now considering just cutting my losses and bailing on the whole Cakewalk thing :-(.
Any ideas would be greatly appreciated
 
please got to youtube and search for "Sonar X1 Midi notes dropout" for an example
 
 
Cheers S

Yeah - the default used to be 500, and it was changed by Cakewalk a couple releases or so back.  I have seen it work at 250 fine for some, and for others, putting it back to 500 or upping it to 750 seemed to work better for them.
 
Bob Bone
 

Not sure about the specifics with X1 (my memory doesn't go back that far, LOL) but SONAR does support free external MP3 encoders, like LAME.