zonealarm pro version 4.5 or 4.0 ? whcih one is safer , stronger?

From: victor marco (anonymous_at_discussions.microsoft.com)
Date: 12/30/03 

Date: Mon, 29 Dec 2003 23:51:15 -0800

As for winxp users, many of us are using zonealarm pro v 4.0

however, one month ago, the zonealarm site says that it has newest version of version 4.5, but only upon extra-payment

please help us, do we need to pay us $30 more just for a minor improvement or

are our zonealarm pro v.4.0 enough for all hackers and trojans ?

please criticise..so that we learn more and protect more...