Then you toggle these layers, are they nested comps with 3D layers in them?
yes, I believe so;
I think I figured it out though, at least partially---when toggling, for some reason, the comp's position gets reset to the origin (0,0,0) and that is why it was disappearing;
really strange still, I wonder why that would happen
Sounds like you have a camera in your pre-comp. Collapsing transformations effectively removes the Camera from the Pre-comp because it changes the rendering order. It's normal.
A screenshot and a flowchart would help us sort out the problem. There also may be a parenting issue.
As Rick said, when enabling CR, the parent comp camera takes over and any adjustments you have done in that department in your sub-comps don't matter. Similarly, of course custom views are ignored. Also certain expressions may evaluate differently, if you don't use proper code to convert coordinates. Check these things...
thanks all for your help,
but I am not using any cameras in sub comps--- only in the main comp. Yes, their are 3D layers throughout. I will take another look, and post a screen shot/diagram later if I get a chance