I don't think so. There were some issues with the avast! folder access rights, but they can be easily (well, depends on the user level, of course) fixed. Otherwise, I'm not aware of any additional issues with 4.7.
I don't really see how avast! could have caused the original poster's problems. Before the first reboot, avast! was not yet active - the installer basically just put the files into the folder and registered them to be started when Windows boot next time. That never happened, however, because of the corrupted registry hive...