Are you running any kind of Exchange server online backup tool? If so, that may cause problems with the web services port. In the installation, change pop 808 to 4093 and see if that resolves your issue.
If this server does not have Internet access the problem may be with the certificate revocation checking that SnapDrive 6.0 does. Go to Internet Explorer select Tools, Internet Options, Advanced. Then under security find "Check for publisher's certificate revocation" clear this option.
I ran into this same error with Windows Server 2003 SP2 with SnapDrive 6.0.1. It turns out that if you don't have .NET Framework 3.0 _SP1_ installed, it can this error too. Make sure you have SP1 .NET Framework.
Nick - we have a snapdrive listener port that will not start on port 808 due to evault service. We attempted to change SnapDrive to port 4093 - but cannot determine how to configure SnapManager for Exchange to talk to SnapDrive over port 4093. We modified 3 config files that had many references to :808 and got it to sort of work - but continued to get errors. If you know how to do this - please advise.