Well it looks like the fix is to apply http://www.symantec.com/docs/TECH192580.
For the Windows 2008 64-bit site server, I updated the machine.config in two places and rebooted. My machine.config was found under:
C:\Windows\Microsoft.NET\Framework\v2.0.50727\CONFIG
C:\Windows\Microsoft.NET\Framework64\v2.0.50727\CONFIG
Making a backup of the files before editing is always a good idea, but what you have to be careful of is this:
You may find an entry already in the file like this: <runtime/> (a self-opening and closing statement)
Just delete that line because you need to replace it with the below which is very similar but has the closing slash in the correct place! Don't just try to add the top two lines like I did! :)
<runtime>
<generatePublisherEvidence enabled="false"/>
</runtime>
I'd still like to know what this service does though - is it just for Deployment Solution which I'm not using???