Yay!
I suspect that the issue in Howard's case was the blocked IP, although it's weird that he could get in by bypassing the linksys if that were the only problem.
The way such home networks normally work is that the cable modem uses something called NAT to share its one real world IP address with all the devices on your home network; the cable modem then usually assigns a non-real world IP address (from the RFC1918 range, generally something like 192.168.x.x) to whatever device is plugged into it's ethernet (hardwire) port. In turn, the Linksys can either be configured to pass through DHCP control to the cable modem, or the linksys can also run NAT and DHCP itself, usually using a different pool of IP addresses (so if the cable modem is handing out 192.168.0.x, the linksys might be configured to hand out 192.168.1.x addresses).
Computers on the internet ignore all RFC1918 addresses like the 192.168.x.x range, which are specifically reserved for "intranet" use, so orchidboard (or it's ISP) doesn't know about your linksys being there or not!
For taking the linksys out of the equation to lift the apparent "ban" on orchidboard, the problem must logically lie with the linksys router in some way, and it logically must have something to do with some content filtering/firewall. If other sites on the internet work, it cannot logically be some kind of local IP misconfiguration, or pretty much everything would break.
I do find that the WRT54GL is somewhat temperamental, for instance, if I add another MAC address to the "allowed" MAC address list in the wireless security settings, this won't actually work until I power cycle the router. This may also be the case with other firewall type settings.
Glad you're back on board.