Custom theme sounds test OK but do not play when actual event occurs

I placed the custom .wav files in the media folder and pointed to them for the events I wanted the sounds to be used for. They all test OK and I have in fact applied the sounds. Problem is they do not play when the actual event; ie, Windows Logon occurs.
Everything looks like it should be working but no sounds are heard.

Anyone have any ideas why this is happening...I'd appreciate any help.

I have a similar problem trying to get 'New e-mail Notification' to work but the 'test' button in 'sounds' in Control Panel 'sounds' does not work. When using the PC, sounds occur as they should for certain events but not the e-mail notification. On my Laptop everything works perfectly using the same wav file for e-mail alerts. Is there a registry entry to get the test sounds to work and e-mail alerts to work on my PC?