no, but I just rememberd a piece of pertinent information that I left out.
When I first tried to install steam to the D drive, I simply changed the install destination to "D:". (I thought the installation would automatically create the "Steam" subdirectory, but it did not.)
Needless to say, I didn't want all the Valve files in my bare D drive, so i uninstalled it from that location, and ever since, it won't work to any other subdirectory.
I should also mention that upon uninstalling, the uninstallation inexplicably deleted some of my shortcuts originating from other unrelated programs on the d drive, but the programs themselves work fine.
Jeez, did I screw my filesystem or somthing?! : O