If you have an effect on the master (such as compression) that can lower the dB level, wouldn't that produce the exact situation you are describing.  That is the buses feeding into the master would be hotter than the master itself after the master effects are applied.

cparmerlee
If you have an effect on the master (such as compression) that can lower the dB level, wouldn't that produce the exact situation you are describing.  That is the buses feeding into the master would be hotter than the master itself after the master effects are applied.

Welcome to the forum.
 
In the case that the OP presented that is not the problem. What he is concerned about is the master buss feeding the main outs and the main outs showing a higher level. It should be the same level. Effects or not. 

OK, you guys solved it!
 
I had recently replaced the original bass with Scarbee Rickenbacker (Kontakt) and also replaced the Acoustic Legends mandolin with one from Bolder Sounds.  In both cases, the tracks defaulted to VS-700 Main instead of Master, which was causing the level discrepancy and a great deal of mix confusion.  Obviously, the bass was the big contributor.  (Not sure why the tracks did not default to Master: I have it set up as the default bus.)  This particular project has 63 tracks and several buses (orchestra, female vocals, etc.) so I stupidly missed this routing issue.
 
In addition to solving the problem, I think we had some excellent discussion here.  Many thanks for the great conversation.

Excellent thread guys!

Glad you got it sorted, Konrad.
 
It's so easy to miss things like this and spend hours trying to track them down.