You should not be having this problem. I have been using Reunion from the beginning, currently up to version 8 like yours, and I have also kept my Mac OS updated to the lastest version. I currently run Reunion 8 with Mac OS 10.4.6 on both a Powerbook G4 and and on a PowerMac G4, and I have never had a problem with any Reunion updates on any Mac OS updates. All installations and upgrades were simple and straightforward and with no complications. My experience is that Reunion is virtually bullet proof, so if it isn't working for you, you either have a bad disk, or some other anomoly outside of Reunion.