Last night I've tried to install Visual Studio ‚Orcas' RTM, but the setup kept crashing at the fisrt step of the installation (installation of the 3.5 framework). Digging into the setup log files I've traced the problem to the installation of the 3.0 framework SP1. After some trials and misses (I've even uninstalled the MacAfee antivirus), I've downloaded the framework 3.5 setup redistributable (the full install package). The setup went flawlessly, and after it ended I was able to install the new Visual Studio.
I hope this information will help someone in need.
