Screensaver problems

Well, I'm new to Win7 and I want to have the screensaver enabled on the Welcome/Login screen. I followed the registry hacks at No screen saver at Windows 7 welcome/log in screen., and now the screensaver launches but I only get sound and a black screen. When I try to access the settings by pressing Space I get the following error:

"The instructions at 0x0042617c referenced memory at 0x00000010. The memory could not be read.

"Click OK to terminate the program."

I leave my computer on at night, and I don't want the Welcome/Login screen to be stuck up there until the monitor sleeps. I have this on a 32bit system, but may be needing to do this on a 64bit machine as well.

Also, I run the screensaver fine when I lock the machine, but want to have the same function when nobody is logged in.