Turning on Scroll Lock causes SONAR's GUI to stutter... For instance, the play marker along with track meters etc., will move every second - like a one-frame-per-second kinda thing.

Has anyone else ever experienced this glitch?

This is not a glitch  - this is intended behavior.
 
This feature allows you to disable continuous graphic updates for meters etc (e.g. on less powerful DAWs) if performance is critical (e.g. recording long takes or live shows where you don't need to monitor channel levels on a millisecond basis)
 
Hit SCROLL LOCK again and it reverts back to normal ... 

FreeFlyBertl
This is not a glitch  - this is intended behavior.
 
This feature allows you to disable continuous graphic updates for meters etc (e.g. on less powerful DAWs) if performance is critical (e.g. recording long takes or live shows where you don't need to monitor channel levels on a millisecond basis)
 
Hit SCROLL LOCK again and it reverts back to normal ... 

Well, I'm accustomed to turning off the auto-scroll feature and it works fine when I do that, but every now and then, I'll get this crap and this is the first time I realized that it's been the Scroll Lock all along.

It's not consistent because it's doing one thing now but at another time it's doing something else.

If this is the case, how am I supposed to turn off the Auto Scroll feature?

Hit the Pause key.

Bristol_Jonesey
Hit the Pause key.

That's the same key I use to turn Auto Sroll off/Scroll Lock on

So what's the problem?

Ok. So, I use the 'Pause/Break' key to turn Auto-Scroll off. And it works fine; SONAR stops scrolling on its own when the play marker approaches the end of the screen, but a couple days ago, when I hit that same 'Pause/Break' key, it started doing this start/stop, 1fps kinda freeze and unfreeze thing. It's the first time it's done that on my new computer, but I've witnessed it a lot on my older computer. Now I know what may have been the reason; the 'Pause/Break' key.

My question is, why is it only doing this now? And is there another way to turn off the Auto-Scrolling feature inside of SONAR?

Not that I'm aware of.
 
What should be happening is this:
 
Scroll Lock = stops Sonar from scrolling in Track View
Pause/Break = conserves cpu and will result in "jerky" screen movements.
 
It sounds like your keyboard has got the 2 functions inverted somehow.

Sounds like maybe a Laptop or a Reduced key (Logitech?) keyboard(?) - no dedicated SCRL LCK(?)

SONAR does have two scroll lock functions that operate independently - one is by the Scroll Lock key, and the other is by Left/Right Click Locks Scroll function in Track View Options. The latter is disabled by clicking in an open area of the clips pane. And it's possible to have them both enabled at the same time so you would have to both click the clips pane and hit the Scroll Lock key to get scrolling back.
 
"CPU Conservation Mode" that reduces the GUI update frequency to 1/second is toggled on/off by the Pause key. This function is independent of the Scroll Locking as far as SONAr is concerned.
 
If Pause and Scroll Lock are on the same key you'll have to consult you system/keyboard manuals to determine how they're differentiated.