Mike, thanks for taking the time to respond. It is truly appreciated.
Based on what you said, I installed a different player (Nero) to compare to Windows Media Player. What I noticed was very strange; each of them exhibited the increased gain when played seperately. However, when I opened the first player, and kept it open, then opened the second player, it look correct.
So, until I figure this out, I guess I’ll need to run 2 players at the same time to get the correct results. If anyone knows of a solution to this bizarre issue, please let me know.