I  recorded a drum track with Superior Drummer a few months back and now I'm hearing random missing hits.  For instance, the intro has a steady 1/4 note closed hi-hat that doesn't sound at times when it should.  If I restart the track those same hi-hat hits suddenly are present.  If I then restart the track again those hits will be missing again.  It's very random and it's not just the hi-hat.  Some times the snare will drop out for a beat or two only to reappear the next time I play the same passage.
 
Also, when I freeze the drum tracks their volume almost doubles.  If I then un-freeze them they drop back to the original volume.
 
I'm guessing the drum tracks are somehow becoming corrupt but I don't know how to remedy the problem other than to remove them and recreate them from scratch.  The thing is, this song is about 3/4 of the way finished.  I'd hate to have go back and start again.
 
Any thoughts? 

As a test, copy the performance data... and paste that into a new/empty Sonar project.
Does the problem persist in the new project?

Jim Roseberry
As a test, copy the performance data... and paste that into a new/empty Sonar project.
Does the problem persist in the new project?

Hey Jim,
 
I'm still loving this workstation you built!  Great job!
 
Thanks for chiming in.  I'm at work at the moment but will definitely give your suggestion a try tonight...thanks!

What you are experiencing is probably a lag while SD is loading samples. The first time through, not all samples have been loaded yet. The second time, they've had time to load.
 
In the lower-left of SD's UI there are windows that show how much RAM is being used, and the message "loading samples...". Open a project and immediately show the SD UI, and you'll see the "loading samples..." message while the number in the "Loaded" window will be incrementing as samples load. Wait until the "loading samples" message goes away and your drum track should then play without missing notes.
 
If you have the "Cached" option enabled to save RAM, samples do not load until they're needed, so it's necessary to play the song once all the way through to load up all the samples. Since it takes longer to load them than it does to play back, some hits might not be heard the first time a given instrument or articulation is activated. Caching will, however, greatly reduce your RAM usage, often cutting it in half.
 
The volume increase on freezing is due to a bug in SONAR that's been around since SONAR 8, in which mono outputs increase by 3 dB when bounced or frozen. I just routinely drop frozen drum tracks by 3 dB using the trim/gain slider. It only applies to mono outs, e.g. kick and snare.

Sometimes missing notes are the result of too small a value in Preferences > MIDI > Playback and Recording "Playback Using nnn Millisecond Buffers". Try increasing it from the default 250 to 500 or 750.

Bitflipper,
 
I've not noticed this issue before this past week with this project.  It seems odd that it would suddenly start happening.  Your explanation does, however, make sense.  I'll check SD to see if I have "Cached" turned on.  At lunch today, I did try copying the performance data to a new project and I got the same spotty results.

Bitflipper had the right answer...problem solved.  May thanks to all!

I reported it under the new AJAX Enhanced Cakewalk Problem reporter (which now takes twice as long to enter reports down to extra button presses and extra form validation  ).
 
Cheers... CWBRN-26314

CWBRN-26314 now submitted to development.