Thanks to admin for the info on needing to update DirectX and WMP.
That did the trick.
Thanks to Dale on all your assistance as well. If the recommendations to update those components are included in the "YES. I updated my system." checkbox part of the install, I must have overlooked those.
Running the 4.22 upgrade was straight-forward.
FYI - there was nothing in Windows Update that showed a need for DirectX updates. You need to run dxdiag from the run command. I went ahead and ran the end user latest package for DirectX from Microsoft and confirmed several new files were installed. I upgraded WMP to version 11, ran the rest of the subsequent Windows Updates, and power-cycled my PC.
All the songs now play correctly no matter how many key changes I make.
YAY!
Thank you for sticking with me through this process. I knew there was an answer. You guys are great.
