Disklavier

Has anyone noticed that the piano music that you buy and play along 
with your own separate CD is sometimes in a very subtle way slightly 
unsynchronized with the rest of the CD?  I have a Mark IV, and it seems 
to me that on some works the piano playing is well done and on other 
works it is sort of unlistenable (like the pianist would be canned that 
night if he were on stage with the band of the CD).  I'm super new to 
Disklavier, so I don't have a broad range of experience with it.  Does 
anyone else notice this?