Could not contact primary server

For several months I haven't been able to update the antivirus, keep getting "Could not contact primary server".

I have Sophos Anti-Virus home edition version 9.2.2.

/Library/Logs/Sophos Anti-Virus.log:

com.sophos.autoupdate: Proceed with manually triggered update from Sophos at 18:19:48 23 February 2015
com.sophos.autoupdate: Updating catalogue information at 18:19:48 23 February 2015
com.sophos.autoupdate: Catalogue updated at 18:19:49 23 February 2015
com.sophos.autoupdate: Error: Failed to get remote version at 18:19:49 23 February 2015
com.sophos.autoupdate: Out of sources at 18:19:49 23 February 2015
com.sophos.autoupdate: Error: Could not contact primary server at 18:19 on 23 February 2015
com.sophos.autoupdate: URL is invalid

Already tried unistalling and reinstalling, and also 2 different ISPs.

Any help would be really appreciated, thanks :)