Just to rule out something different.
 
Do you use a wireless mouse?

I think I tend to get mouse noises intermittently when my WIFI was on. 

I'm wondering if it might be something else, actually a form of popping/clicking, which I'm getting also now (I'm now working on a longer piece with more instruments). So, the zapping noise could be an extended pop/click type thing.
 
I currently have my asio drivers at 512. I know I get better latency at lower values, but maybe I actually a need higher setting, to get rid of the noises?
 
BTW, I'm on Windows 7 Pro 64-bit, if that makes any difference. I've done some things to optimize the computer, which is an i7 with 16 GB ram. Mostly disabling services I don't need. But maybe I need to do more?

Hi
 
i have found a bug which may be different or the same spike / zap noises you hear.
This happens to me when "certain" side chaining and using a second input track weather it be an AUX track inputting the same synth or a Multi timbral instrument like kontakts second onwards input track.
If its the same bug you can test this
 
1) save your project
2) create a test save in a different folder and name it TEST 1
3) reopen TEST 1 ( now your original project is safe and you can find the cause without destruction
4) If using sidechaining DO NOT REMOVE any of those tracks sends or inputs at all in any of the steps below.
****Please advise if using sidechaining because its definitely the BUG then******
5) remove all instruments except kontakt < i mean delete them from the project leaving only kontakt and sidechaining tracks
6) playback until the zap happens, if it does zap then go to 6a, if the zap does not happen go to 7
6a) go to kontakt input tracks two three four etc and change the inputs to NONE ( leaving only the first kontakt track inputting the first instrument.
6b) now playback and the zap cant happen.
7) close TEST 1 without saving, the reopen TEST 1
7a) remove all instruments except vienna < i mean delete them from the project
7b) go to the " Platinum Input" tracks for vienna and change the inputs to NONE for tracks two three four etc ( leaving only the first Vienna track inputting the first instrument ( remember to change vienna inputs inside platinum not vienna )
7C) now playback and the zap cant happen.
 
The above will help you narrow down which synth is causing the problem for you if you keep repeating the procedure until you find it, if it is the spike BUG then when you get to step "C" if the zaps are gone then its the spike BUG because the spike bug occurs at least for me and it took me 4 years to find the SOAB when using more than one input on one synth combined with certain sidechaing regardless of AUX or Multi Timbral, and by changing the 2,3,4,5,6,7,8th input tracks of one synth to none the spikes at least for me go away.
 
Good luck i hope this helps in some way

I am making some progress. Before intensively trying the troubleshooting guides so generously provided by taccess and others, I decided to try reducing the fx load. I turned off all reverb on the synths. I put Breverb on each synth instead. They still all go to Spaces Reverb on its own bus. that goes to Mix, which only has Sonitus Compressor and LP EQ64. That's it. Deleted all fx not being used, turned off fx on all midi insts, as they didn't have any anyway.
 
Doing this had reduced the glitches to one per playback, on an 8 minute long full orchestra piece. some playbacks have no glitches. I'm starting to wonder if this could be a ram issue. My ram is 16GB, but only 1333 mhz, not 1600. I must have decided to skimp on ram when I had the computer built. Now I'm thinking of upgrading to 32GB, 1600 mhz. Does this sound reasonable?