That is a good thought about the facts and dimensions possibly changing but we can rule that out.  In our DW load process, which is the only time the facts and dimensions are modified, the very last step is to run the full process on the SSAS database.

I agree with you that something else must be in play, but we just can't figure it out.  The error messages getting returned from the system are not accurately reflecting the issue (in our minds).

Thanks