Mac: Why does Sophos add items to LaunchDaemons every update?

I have a folder action that will alert me to any changes to startup/lauch folders.

(It is a nice little piece of mind to help ensure that my Mac stays protected)

However, everytime Sophos checks for updates, it re-adds the same "com.sophos.autoupdate.plist" file dated "Thursday, May 9, 2013 3:28 AM":

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Label</key>
	<string>com.sophos.autoupdate</string>
	<key>ProgramArguments</key>
	<array>
		<string>/Library/Sophos Anti-Virus/SophosAutoUpdate.app/Contents/MacOS/SophosAutoUpdate</string>
		<string>-d</string>
	</array>
	<key>OnDemand</key>
	<false/>
	<key>KeepAlive</key>
	<true/>
</dict>
</plist>

Is there anyway to disable this? Is this something on our side or is to common to all Macs?