I purchased the GamersGate version and it works perfectly with the boxed retail game. I noticed in the installer that it went right to the default directory, so maybe if Impulse installed it to somewhere else you can modify that?
That is not a problem because Impulse lets you select an install directory (if you have set it to do so in the preferences). The issue has more to do with the DRM (retail used disc check, the Impulse version uses Impulse::Reactor) and possible incompatiblities there.
