Still having problems with Native Instruments effects on buses.

I've talked about this before but have never gotten any clues as to why it's happening, figure I'd ask again just in case something clicks with someone. 

More often than not, when I load a project, any Native Instruments effects that I have on my buses that are hosted in Guitar Rig have all of their dials zeroed. If I'm using a preset, the correct preset name will be showing, but the dials are still zeroed. I also use Guitar Rig effects a lot on my tracks, but these don't seem to be affected. 

99% of the time it happens with NI's Solid Mix series of effects. I regularly use the Solid Bus Comp and Solid EQ on buses. A couple of times though, it's happened with large Guitar Rig effects chains I've had set up on a bus. It's gotten to the point now where loading a project means I have to go through all my buses and manually load a saved preset on each of the effects before I start playback, which as you can imagine is a pain. 

To be honest I'm too much of an amateur to get to the bottom of this myself and I could use a clue or two. I've asked on NI's forums but have gotten nothing but crickets. What I have to go on so far:

1) It never used to happen to me with Pro Tools, just Sonar X2a
2) It only ever happens on buses, not tracks
3) The effects it happens with are Solid Bus Comp, Solid EQ and Solid Dynamics, although it has happened with an entire Guitar Rig effects chain before
4) The effects are hosted in Guitar Rig (because as I'm sure most of you are aware, virtually all of NI's effects have to be hosted in Guitar Rig although they're starting to roll out exceptions to that now). 

Any ideas? 

Thanks Bob.