Default Firewall Settings

I am using 7.0 Beta 1, but it has been upgraded throughout the development, so I assume it is equivalent with Beta 5. I have a 2 pc network behind a router/firewall device, a XP box and a Mepis (and sometimes Sidux) box. I noticed that the default firewall rules are different than from past Mepis versions. I use the XP box's IE7 to test web pages running on a development web server on the Mepis machine, but I cannot connect to the Mepis machine. I can ping from Mepis to XP, but not from XP to Mepis. I also used a RC3 Mepis CD on the XP machine and cannot ping from Mepis to Mepis. When I boot the Mepis machine into Sidux, I can ping from XP to Sidux and back again. I do not believe I have a network issue, but must be due to Mepis's default firewall setup. I do not run Guarddog (past versions and present) and have not had this issue on past versions. I assume this change is to allow better protection after install or for the live CD (for laptop coffee shop users?), but would it be helpful if during the install a basic wizard could be included to tweak the firewall rules for different users?

I assume to tweak myself, I would use Guarddog or flush the rules and tweak with iptables? Any advice?