Peter,
First, double check if you have the latest Viewer installed and Host package downloaded. As of now, March 4 2014 the latest version is 5.6.0.6.
Secondly, make sure that you don't do any prior configurations on that Host file , because the default option for the Standard MSI option is to overwrite the Host package. So you might end up with an already configured Host package accidentally. In other words, it should be a purely vanilla Host package freshly downloaded from the site.
Hope that helps.
