Sophos Client Firewall: following a downgrade the log viewer displays incorrectly

Issue
If you downgrade Sophos Client Firewall from version 2.0.0 to 1.5.3, the log viewer and its content may display incorrectly.

Sophos product and version
Sophos Client Firewall, version 1.5.3, following a downgrade from version 2.0.0.

What to do

1. Close the Sophos Client Firewall log viewer.
2. Go to C:\Documents and Settings\<username>\Local Settings\Application Data\Sophos\Sophos Client Firewall. (The path may vary slightly according to your operating system or set up.)
3. The Sophos Client Firewall folder contains three *.ini files. Delete all of these.
   This will delete any remaining custom settings for the log viewer, including, for example, custom filters. The log should now display correctly.