I have an ongoing problem with a GR-hosted Native Instruments compressor on the master bus, in that it's silent whenever I first load the project. I have to "kick start" it by clicking on a preset. I'm fairly used to doing that now. I know it must be a Sonar problem because I used the same compressor in my Pro Tools projects without ever having a problem.
I've also experienced problems with a Reflektor reverb effect (again hosted in GR) on my reverb bus. That time, the project would always load with the wet/dry knob turned all the way to dry, and everything panned hard left.
Now a project that makes some extensive use of Guitar Rig effects chains has suddenly decided to start loading with every single knob turned all the way to the left. On the chain I'm looking at now, that's 24 knobs, which I had so carefully set up last night, turned all the way down. I'm back to square one. On the couple of effects on which I'd used a preset, the preset is loaded (i.e. showing in the preset window) but still all the controls are set to zero. It's really annoying. I just have no confidence with Sonar and Guitar Rig effects any more.
I'm guessing this is a NI/Sonar compatibility issue because like I say I had none of these problems with Guitar Rig in Pro Tools.