Turned on my Mac this morning to get an automatic 'Please Upgrade your software' request when I turned on Firefox which I duely did. I pressed the button, downloaded the dmg and then dragged the icon as instructed to then get the statement ''This software cannot run on your system''. Why would it ask me to upgrade if I cant run the software now and cant find an old version to replace it with?? I now have to use Safari which has really put a downer on my day!!!!