This has been solved, thanks. Bounce buffer was set too high - pilot error!
 

Are you using the ASIO driver?
I had a similar problem when I used the MOTU WaveRT driver.

ASIO yes. NO other issues except with Fast Bounce.

I don't know then. I always thought non-real-time bounces should be render it perfectly regardless of how long it takes. The stutter in your recording is pretty nasty (great stuff BTW). Does your RME interface support other driver modes? It might be worth trying an alternative and seeing if it fixes the problem.

Are you running in 64 bit audio engine? If so, try disabling that - I've found a couple of plug-ins that have issues with this and fast bounce (old ReValver for example).

What I am demonstrating is that there is a problem inside the Sonar engine.

Asio drivers should have no bearing on the Fast Bounce as Fast Bounce happens inside the Sonar engine, regardless of soundcard drivers. I have specifically used Sonar plugins ONLY so that 3d party issues can be ruled out. Fast bounce is supposed to let the CPU work at it's own pace thus getting a better result, yet the Audible Bounce sounds better.
 
And no, the engine is running 24 bit, not 64 bit double-precision.

Maybe it's a setting, but what could it possibly be that causes this? I have brought this issue up before and the both Seth and Craig told me I was mistaken. Hence the audio clip. Any ideas Bakers?

Hi, you might try to increase the Bounce Buffer Size.
 
Preferences > Audio > Configuration File > Properties
On the first line
BounceBufSizeMsec 
 
By default this is 0. 
Try to increase this to maybe 50. The max is 350.
 
There is more info in the Help File under Aud.ini
 

Well whadya know. Mine was set to 350. I reduced it to 0 and now it works. Seems counter-intuitive, but there it is :O) Thanks Keyzs for reminding me of that parameter!

Cheers friend... glad it got solved

great track too