I think I might have this solved. I looked at Big Al's list and saw some of the same programs I'd browsed at Snapfiles.com. I went back there looking for Vista compatibles, finding few of them.
Finally I went back to the player I've been using all along - STP Player, a Russian masterpiece in my opinion - and got the most current version from the developer's website. When I frist tried STP on Vista (when I originally got the PC in November) , the OS wouldn't run it.
But now I disabled the very irritating User Account Control (the feature that has Windows tell you your PC isn't really YOUR PC) and replaced it with trusty Win Patrol.
I have a feeling that a lot of Vista issues are actually the fault of the UAC rather than OS changes or running a 64 Bit system. We'll see if I'm right, so far STP is running like a dream: silent, in the background, responding to custom shortcut keys, eliminating duplicate playlist entries - this is all I wanted in the frist place. I've been using STP for years and I hope putting a bullet into the UAC alows it to operate unhindered from now on.
Thanks to all who replied.
Bloated, unstable WinAmp is gone, STP is just fine for me.
You ever listen to K-Billy's Super Sounds of the Seventies?