I experienced this as well and the "fear" of it repeating made me default to a work-around that is not particularly "fun" and removes the ability to see the rest of the project :( I opened the audio from the track I wanted in stand-alone mode and could work with it just fine, save it, and pull it back into SONAR. This also had the advantage that Melodyne is not even in the SONAR project at that point, but undermines its effectiveness as a plug-in.
The "once bitten, twice shy" scenario...
I need to test OP again myself to be sure if it is repetitive.