InstaDMG installing Growl opens Boot Machine’s System Prefs

Ok, this is weird. I threw Growl into the build stream, and it appears to install fine. Today i was watching it out of the corner of my eye and when InstaDMG reported it was installing Growl, my system prefs opened. This explains why every time I leave it to build overnight, I find my sys-prefs open the next morning. It does not seem to effect the build process or the install of growl. Its just really odd. No errors reported, nothing else out of the ordinary.... just weird. Any ideas what is happening? Anyone else see this happen? I also install safari growler, if that gives any clues. knowmad