installed the new SDC first.
Showed DX and WB6 updates available, clicked update now. DX installed. Got the 'previous version of WB must be uninstalled first. Did that. Rebooted. Naked Computer

Opened SDC, no update prompted, but showed WB6 as available to install. Installed, rebooted.
Working as expected. VERY NICE!!! On XP no less. It might be just in my head, but there *seems* to be more areas allowed to be transparent/translucent.
Even got an unexpected bonus: The new SD skin "Diamond" allows for full window drags, not just the outline. (my graphics card isn't up to spec) It's a little slow, but still. It's the only skin which allows that. That skin seems to slow everything else down. Don't know why. Changing to anything else clears up the slowness.
My only beef is that changing skins is now very, very slow.
There is a process showing up called "WBINST~2.exe. Don't know what that is, haven't tried killing it, but it won't go away on its own.