Time line jumping instead of scrolling

Until very recently, the scrolling time-line cursor had behaved flawlessly (regardless which time ruler format was selected).
Yesterday I opened a project that was barely begun - 12 tracks for Session Drummer, one instance of Dimension Pro and one audio track - and hit the spacebar to play what I had. It played correctly; that isn't the problem. No audible glitches whatsoever.
The time cursor, however, no longer scrolls smoothly along horizontally from left to right... instead, it will jump and hold, jump and hold, as if displaying only a "packet" of data at a time. The meters also seem to respond in the same manner, displaying a "snapshot" at each "freeze" point.
The project is going to have several time signature changes throughout; it begins in 7/4 at 180 bpm, but I don't believe that has anything to do with the display issue, as Sonar now has the same hiccups in ANY existing project I open.
The points at which the cursor "holds" before jumping to the next point are consistent, but not in sync with anything I can detect (measure, for instance). In fact, it seems to be jumping 4 quarter notes, then 3 quarter notes, then 4 again, etc.
I probably "fat-fingered" something to cause this, but I cannot find and correct the setting.
Please help???

Yep. I feel like such a camel.
So glad you were on the job, FBB. Many thanks!

Hilarious!
May you never be spat upon nor infested with fleas!

OlSkoolGuy


Yep. I feel like such a camel.
So glad you were on the job, FBB. Many thanks!

No worries, I think we've all done that at least once as well as scroll lock which will stop the TV scrolling completely. I even managed to do it once on a keyboard that didn't have a scroll lock. I knew what the problem was but not how to fix it. Turns out that ctrl+Pause will act as scroll lock on a keyboard.