Audio pops in Sonar but not other software?

Since the last software update to Sonar x3 Producer, I get audio pops at a rate corresponding to my ASIO buffer size.
 
To hear the pop, I just play one note. 
 
If I increase the ASIO buffer size, the pops are more spaced out, but still audible.
 
I've optimized my machine according to the guide, and been through the help page https://www.cakewalk.com/Support/Knowledge-Base/2007013007/Audio-Dropouts-Clicks-and-Pops-When-Playing-and-Recording
 
This has only happened since the last software update.
 
I've spoken with the manufacturer of my soundcard, a Focusrite 2i4, but since the sound is fine outside Sonar, even in BitWig, there's not much they can do.
 
Does anyone haveany ideas?
 
This is a dedicated Windows 10 i7 with 16 gig, a massive fan, a pretty fast disk, minimum background tasks, fully patched....

TIA
Lee

Didn't look at MIDI budfers -- will do, thanks!

X3 Producer is a different product. Both get updates monthly for a year, or longer for more dosh.

I have X3 producer and the last update for X3 was to version X3e in 2014.  Not sure what updates you could be referring to?  Did you mean Windows updates?
 
Try the current demo of Platinum and see if that works with your rig.  http://www.cakewalk.com/Products/SONAR/Try-SONAR#start
 

Agh, sorry -- when I said Sonar X3 Producer, I meant Sonar Producer. It gets updated monthly for a year, but those updates aren't solving my popping problem. or the regular crashes (ie every few hours) - even the fault reporter can't report faults :(
 
Still, the popping has stopped -- although I didn't change anything....
 
Thanks, all.