“A file in product sophos puremessage had an invalid signature”

Anyone had a similar issue with Puremessage on server 2008 R2 with Exchange 2010?

PM 3.1.0.0 installs perfectly but during the update for the spam detection rules (pmsr)

the update fails with “A file in product sophos puremessage had an invalid signature”

I have removed and reinstalled puremessage twice now and manually deleted the folders and removed all active directory entries but it always fails with the same error during the update of the spam updates. I have contacted support but they told me it was the firewall and that I should wireshark the connection. For one I do not believe this to be an issue with my firewall. C’’’’mon sophos!!!!!  Just to prove a point I swapped the gateway on the server to our spare connection with a different firewall and it was still the same. We have also our old 2003 exchange with puremessage that’’’’s updating correctly.