Thanks for the help. But just for your information, I did all that: uninstalled everything, went through the SDC install, then registered WB5, downloaded and installed. I did uncheck show pre-release because of the troubles I've heard about the beta here. So now it reports that I have 5.00.001 installed. And the system info reports the following:
WindowBlinds 5.0 System Information Report:
STATUS : WB+ SRV+ HLP+ UI+ TRAY+
WindowBlinds is installed correctly on this PC.
WindowBlinds appears to be activated on this PC
Your machine supports per pixel borders on WindowBlinds skins.
You have one monitor in total.
(Dell 2405FPW (Digital)) 1 is attached to NVIDIA GeForce 6200
Wblind.dll 2005/11/28 13:57:10
Wbsrv.dll 2005/11/28 15:52:00
Wbconfig.exe 2005/11/28 16:19:00
Wbload.exe 2005/11/25 19:30:58
Wbhelp.dll 2004/09/18 16:37:00
Wbui.dll 2005/11/20 12:23:40
Tray.dll 2005/11/02 13:28:26
Which means that I had the latest released version all along. Even when I installed on top of trial. So, that's not the problem of why I'm not seeing the proper toolbars. Occam's Razor: maybe it's the skin.
I guess the only thing left to try is the beta since that's the latest builds... more to the bleeding edge we go, hi-ho....
And by the way, if you Apply Changes many times on the same skin (especially these Vista ones) whilst trying out various User Overrides, you can lock up Explorer quite assuredly. I'm very good with killing it in Task Manager and re-starting now... 
But I do appreciate the effort to help sort this out...