Cannot install voxatc

I cannot install voxatc to try the demo. It says that FSX SP2 is required even though I have SP2 - sort of...

I have SP2 installed, but I had to do it via "msiexec /a" and some file copying. SP2 refused to install normally - but it works. I have other add-ons, like the ifly-737 that require SP2 and they work. Everything from SP2 is there, including simconnect.

Is there something simple that the voxatc install checks for in order to detect SP2?

Is there a registry entry that I can add or a file I can edit to get past the SP2 check?

I am running windows-7 enterprise 64-bit.

thanks,

Mike