Every time this happens I toggle the FX all on/off. Or just hit the "E" on the keyboard. Works every time for me. Thanks

The more I think about it, the more I think it's my interface.  I have a Roland Quad-Capture that has been a bit of a disaster.  The 48v power died on it after I had it about a year, and the USB power cuts out completely on occasion.  I've swapped the Roland for an old Line 6 UX1 I have.  We'll see how that does.
 
My sincere thanks to EVERYONE who answered my distress call.

jude77
The more I think about it, the more I think it's my interface.  I have a Roland Quad-Capture that has been a bit of a disaster.  The 48v power died on it after I had it about a year, and the USB power cuts out completely on occasion.  I've swapped the Roland for an old Line 6 UX1 I have.  We'll see how that does.
 
My sincere thanks to EVERYONE who answered my distress call.

That would make sense, except that we're experiencing the same thing, even though our interfaces are very different. Mine is an M-Audio Audiophile 2496 sound card and at least one other has similar difficulty using a Focusrite. There's also the fact that it only occurs when using SONAR.
 
Have you had these issues outside of SONAR? Please let us know what happens after using the Line 6.

TimV:
I'll be glad to.  I should know in a day or two.

Here's a closing addendum to this thread: since changing my interface I haven't had any more problems.  Apparently my quad-capture was a dude.  Hope this helps

I only just read the thread but already at the top I thought ... seen that - that's the damn Roland driver again ...