I'm hoping it's something stupid that I'm just missing. About a week ago I changed my network configuration to the following:
Internet -> DSL Modem -> Windows 2003 Server (firewall, router, and DHCP server) -> Wireless access point (DHCP not enabled)
It's been working fine. We have two laptops and a few devices all running on the wireless network. All of a sudden tonight one of the laptops (a Dell Inspiron 2200 with Windows XP) started having trouble accessing web pages. The signal strength will be at Very Good. We'll load a couple of pages and then all of a sudden, FireFox will say "The connection has timed out."
The Windows 2003 Server has a .3 IP address, the wireless access point has a .2 IP address. The laptop currently has a .21 address, which it's getting via DHCP. From DOS, I can sometimes ping the server; sometimes it times out. I can reliably ping the wireless access point. I can also reliably ping the other laptop on the wireless access point. I can also ping the problem laptop from the other laptop on the wireless access point. From the diagnostic tools on the wireless access point, sometimes I can ping the problem laptop and sometimes I can't.
If I disable the wireless network card and plug the laptop in via ethernet, it works fine.
We've rebooted the laptop, the wireless access point, and unplugged and plugged back in the wireless access point.
I'm at a loss... any ideas?