This is so weird and frustrating. One of my current projects (only one of several) was giving me random, intermittent half or whole second long pauses during playback (analog sum mix down). So I started a new, blank project and copied and pasted each audio track (plus two soft synths) to the "clean slate". After rebuilding the project this way, the new version played back fine smoothly...yay! THEN, after I decided to switch out my Superior Drummer sound pack from Music City to Rock Warehouse, PRESTO! The playback pauses are back, just as before!! Anybody ever experience a similar gremlin? I already tried deleting my aud.ini file the first time around, and that didn't help. Yeah, I'll stick with Music City IF nothing else ends up bringing the pausing back, but any input is much appreciated...thanks!

SONAR Platinum Kingston
Windows 10 Home Premium
6 core 3.3 ghz i7
16 GB RAM
1 TB system hard drive
128 GB SSL audio drive
2 RME Multiface II's linked via ADAT

I found the following helped in a similar situation (moving audio clips whilst playback is looping stopped audio engine)
 
Preferences>Audio>Sync and Caching
 
Under "File System" switch on "Enable Read Caching"

Hmmm...OK, thanks, J, I'll try that, though I thought Cake generally recommends leaving that option unchecked. But it's worth a shot, thanks!

Hi baberufus, I have the same 'symptom' on my system. It's just as if all of Sonar freezes for a split second. Have had the issue show up on several occasions and in different projects, also during recording.
I really can't put my finger on it.....tried changeing all kinds of settings without result. The first few times it happened the project had Addictive Drums synth running so I thought it had something to do with AD but later it happened without AD as well.
I have been waiting since before Kingston update to reinstall my system...already did a clean install of Win10 and now that Lexington is out I will do a clean install as soon as I find some time..(maybe next week) and hopefully won't get the stuttering anymore. I don't have much time for my home-studio at the moment so it isn't bugging me much.

Thanks, M, yep, I'm afraid that I'll come across this same bug when I work more extensively on my other projects. Downloading the latest Sonar patch is something I will do, but of course it's always way too easy for that alone to be a fix…lol!
 
My next course of action, should I require it albeit reluctantly, is to rebuild the project in Reaper and see if the same thing happens there. I am more used to Sonar and it's obviously a more powerful program, but I've occasionally used Reaper over the past few years since it's so cheap and actually a great app for the money. Sonar obviously has better features, but Reaper doesn't seem to have any weird performance glitches, at least that I've seen so far.