Intermittent MIDI Playback delay

Im working on a project that currently has apprx 10 tracks.  3 audio and several MIDI. 
As I work on playing ideas out on an audio track, playing them back with the record armed and input echo selected on the track Im working on, maybe 1 or to of the MIDI tracks will be/go out of sync. If I select the PDC on the tool/control bar, they will sync back up into time but then the delay will be on what ever Im playing at the time (guitar, ...audio track).  If I disable the PDC on the control bar, the effect/delay reverses and goes back to Midi being out.  Other Midi tracks will not be effected.  This tends to be an intermittent problems.  At times everything works great with no issues of delay/latency.   Wierd, kinda like its my computer and not X1 settings? 
Any thoughts on intermittent causes?
 
Ill add my setup to signature as soon as I post this add.

Maybe this will help:
http://www.cakewalk.com/Support/kb/reader.aspx/2007013236
 
You will see that I have a thread going here about some similar issues:
- Sometimes MIDI instruments get behind (lag)--sometimes not.
- Sometimes MIDI instruments just stop playing--even when I click on notes in the Staff view.

I have increased the MIDI buffer to the recommended max and have a really powerful new PC, so I don't think it is a memory or buffer issue.

I can fix this by clicking the Panic button (the MIDI reset button).  It usually happens after I start and stop the track a few times while working.  Some of the thoughts on the forum are around something (maybe bug or maybe not) sending some kind of CC7=0 message to random instruments.

May or may not be related to your issue.