The Imp,
No, I was not using Steam to run my BWS install. Instead, I was using an "EET" icon on my destop to run the game, which connected to the Baldur.exe file in my Baldur's Gate II Enhanced Edition folder.
It was just my frustration at constantly having my BWS game crash at startup (and generating a crash dump file) that I tried alternate ways to start the game, including using the Steam menu. That's what led me eventually to doing the "verify integrity of game files" option in Steam, which in retrospect was really dumb.