This is a strange situation. I was trying to help a single mom with a small home network (multiple machines behind a single DSL connection). However they purchased two new eMachines from Best Buy and a Linksys BEFSX41 (the Linky was my recommendation for the functionality/price). I've installed several BEFSX41 units for many home users and they have been very stable. But in this situation, neither of the eMachines can browse or send SMTP while the firewall feature in the BEFSX41 unit is enabled. They can however send constant ICMP packets to any external host (even extended pings of packet size up to 1500 bytes) without a single loss of packet. If I put my IBM Thinkpad behind the Linksys, I don't run into any connectivity issues, only the eMachines. I confirmed speed/duplexing wasn't mismatching between the eMachines and Linksys. Made sure the native WinXP firewall was disabled. All Win patches are update-to-date, Norton '04 is current and Ad-Aware/Spybot etc have been installed, updated and scanned without anything found. I can rule out hardware conflicts between the Linksys & eMachines due to it working just fine with the firewall feature disabled on the Linksys. So I'm at a loss on what could be conflicting on these eMachines when connecting through a external hardware Stateful Packet Filter firewall...??? Has anyone run into this before? 
