Blogospherianman
I use an addesso tablet for drawing target notes in antares auto tune graphical mode, also for drawing note lines like slow scoops etc. tried it in sonar and the widgets acted crazy so i don't use it for that anymore. It's not you man! Haven't tried since win 10. My waves dials were squirly with even a mouse with win 7, but win 10 fixed that. I'll check my widgets when i get home.

Thanks for the confirmation, I was going a little nutty with this one!
 
The mention of the OS version might be key here; I've noticed this behavior on Win XP and 7, but haven't tried any higher versions yet (I remain pretty gun shy about 10...this machine will need to run PT for a while, and if you look at that program funny, it'll make your life hell stability-wise).

I can fully confirm that is is resolved and working awesome in Win 10!! This makes me happy. Most upgrade screw things up. My dials and widgets are HAPPY!! Glad I upgraded while it was free. (still made a back up sys image before hand just to be safe!) Smooth upgrade too, didn't have to re-install any programs and so far (knocking on wood, salt over the sholder) everythings working great. I have it set to metered connection so it hasn't updated to the anniversary update yet. some having issues. Hope that helps!!

I use a wacom tablet as a mouse supplement and I have noticed some inconsistency inside Sonar - mostly right click related issues but nothing I can't work around.
 
I got this good bit of advice from another sonar user:  Also, this was new to me, but my tablet is behaving WAY better in Sonar since going into the Win10 pen and touch control panel (not Wacom's panel) and disabling the "press and hold" and "flicks" features.  
 
Helped a lot with the knobs jumping around thing.

Blogospherianman
I can fully confirm that is is resolved and working awesome in Win 10!! This makes me happy. Most upgrade screw things up. My dials and widgets are HAPPY!! Glad I upgraded while it was free. (still made a back up sys image before hand just to be safe!) Smooth upgrade too, didn't have to re-install any programs and so far (knocking on wood, salt over the sholder) everythings working great. I have it set to metered connection so it hasn't updated to the anniversary update yet. some having issues. Hope that helps!!

Aaaaaw man, you're gonna make me regret not updating to 10 while it was free :)
 
Thanks for the input, it's good to hear!

xiwix
I use a wacom tablet as a mouse supplement and I have noticed some inconsistency inside Sonar - mostly right click related issues but nothing I can't work around.
 
I got this good bit of advice from another sonar user:  Also, this was new to me, but my tablet is behaving WAY better in Sonar since going into the Win10 pen and touch control panel (not Wacom's panel) and disabling the "press and hold" and "flicks" features.  
 
Helped a lot with the knobs jumping around thing.

Thanks, I'll see if there's an analog to these features in Win 7 and report back.

Checked it out. Those settings are in Win7 for sure, but they don't fix the issue. I also tried running with the MS included driver (which enumerates the tablet as a mouse), no help there either.

I guess it was time for the AHA! moment.
 
The issue appears to be the difference between absolute and relative coordinate settings in my tablet driver. 
If I have the driver set to "absolute", the digitizer behaves like pen-on-paper: fixed screen locations correspond to fixed points on the physical tablet. This is the intuitive setting, but it causes the offending widgets to jump like mad.
 
If I set to "relative", the tablet behaves more like a mouse, ie: the pointing behavior picks up from where you left off. It's a really weird setting to enable, but it does make the widgets usable. Not as graceful or intuitive as the 'absolute' setting, but probably something that can be learned to be dealt with.  I'll have to play around with this for a while to see if it'll be an acceptable work-around. 
 
Thanks for all the help, folks!