Issues registering C++ COM DLL on 64-bit Windows 7

I have a simple C++ ATL COM DLL and a 32-bit Visual Studio Setup installer. All is well on 32-bit Windows开发者_JS百科 but there are some issues on 64-bit Windows 7.

In addition to HKCR, my RGS script adds some registry entries to HKCU as well. After inspection with Registry Editor it turns out my keys aimed at HKCU ended up in HKEY_USERS\.Default. What went wrong? I can't seem to get to the bottom of this.

[Edit]

When I do a manual c:\windows\syswow64\regsvr32 on my COM DLL, I finally get proper keys in the HKCU registry. Does this mean Windows Setup project is broken on 64-bit Windows?