I can't make it happen with X3 or Platinum, nudge continues to work after quantizing for me.
 
Perhaps there is more to it? 
 
Can you start from a blank project.  Add just a MIDI track (nothing else) draw some notes in the PRV, select those notes, quantize and then have nudge not work?  What exactly are your nudge settings?

msorrels
Can you start from a blank project.  Add just a MIDI track (nothing else) draw some notes in the PRV, select those notes, quantize and then have nudge not work?...

 
OK, I've just tried that. Same result.

msorrels
...What exactly are your nudge settings?

 
Nudge 1:  single measure
Nudge 2:  1/16
Nudge 3:  4 ticks

By the way, this behaviour only applies when working in PRV. If I select a clip in Track View and quantize, the selected clip nudges ok afterwards.
 

Tomorrow I will have access to another computer with Sonar X3e installed. It will be interesting to see if it does the same thing there.
 
 

OK, I've tried it out another computer. Same result.
 

Very strange. All good here in the PRV as well with X3e x64. Was the second machine also 32-bit SONAR? I had very small nudge values, but larger ones work fine, too. Select some notes, quantize, nudge, quantize, nudge, quantize nudge...; works every time. 

brundlefly
Was the second machine also 32-bit SONAR?

 
Yes, the same, i.e. Sonar X3e x32 running on a Windows 7 x64 platform. Both installations have Sonar X2a installed previously.

Maybe 32-bit specific, then. I couldn't find any references to it in searching the forum that didn't turn out to be due to having Enhanced Editing enabled or clips locked or selection back to 1:01:000 or something like that. You might try binding Ctrl+Numkeys to the same functions for both the TV and PRV, and see if that helps.
 
 

brundlefly
Maybe 32-bit specific...

 
I've also tried it in 64-bit Sonar X2a. Same behaviour again.