Firewall client and IE KB867801

I have several laptops running Windows 2000 connecting to a 2000
network. One of the two servers is running Small Business Server 2000
with ISA server. Each client machine has the ISA Firewall client
installed. The laptops are often out in the field but since this
update they are unable to browse the Internet unless the firewall
client is disabled. This was not the case prior to the IE6 Security
update KB867801. They need the client enabled when on the domain or several
applications will not work/ update correctly. Anyone know how I can fix this? Microsoft sure has been pushing out some junk lately.