well they obviously have different behaviors and yes, the versions are most likely why. my question was, since no doubt Avast 9.0 beta was developed before Yosemite why does it seem to work better on OSX 10.10 than on OSX 10.9.3 or below.

I was just trying to get Avast to install correctly in OSX 10.9.3 but I’ll use something else.