Scripts, registries, screen-savers, oh my!

I'm trying to use a screen-saver on a Windows XP 64 bit machine which uses a .NET app which makes an interop call which relies on some x86 Shockwave Dlls (some Shockwave animation). Everything should be in the %systemroot%\WINNT\SysWOW64 directory. When the timeout for the screensaver occurs, the process should looks like this:

Screensaver.scr -> .NET app -> shockwave animation.

During installation I want a vbscript to my screen-saver file to copy the Screensaver.scr to the SysWow64 directory and then set the proper registry key to this file for Windows to launch the screen-saver.

The code is something like this:

Dim sScreenSaver, tScreenSaver
sScreenSaver = "C:\SourceFiles\bin\ScreenSaver.scr"     'screensaver
tScreenSaver = "C:\winnt\SysWOW64\" 

Set WshShell = WScript.CreateObject("WScript.Shell")    'script shell to run objects
Set FSO = createobject("scripting.filesystemobject")    'file system object

'copy screensaver
FSO.CopyFile sScreenSaver, tScreenSaver, True

'set screen saver
Dim p1
p1 = "HKEY_CURRENT_USER\Control Panel\Desktop\"
WshShell.RegWrite p1 & "SCRNSAVE.EXE", (tScreenSaver & "ScreenSaver.scr")

After installation, I can verify the the Screensaver exists in the correct directory. (It actually seems to be in both the system32 and the sysWOW64 directories---whether that's the install script or something I did post-install I'm in the process of verifying.)

However, the registry entry is not correct. In both the 32 and 64 bit regedit I see the HKCU\ControlPanel\Desktop\SCRNSAVE.EX is set to:

 C:\WINNT\system32\Screensaver.scr

This isn't right. The screen-saver won't run from this directory. It only runs from SysWOW64. If I manually edit the registry with regedit to the correct SysWOW64 path everything works fine.

Is this a problem with using the script or is this a Windows registry redirection, or filesystem redirection problem? You'd think this would be simple...