I occasionally have trouble connecting to other computers on my network through wireless.

Here is my setup
Router: Buffalo WHR-G125 running dd-wrt (acting as Ethernet hub and WAP)
Server: Dell Dimension running Xubuntu (running Apache2, openssh, Dovecot-imap, and dnsmasq)
Laptop: Powerbook G4 running Mac OS 10.4.10

I have all my computers set up with static ip's. I have my laptop configured so that it will have the same network setting whether connected through ethernet or through wireless (ip, subnet mask, gateway, and dns servers). When the ethernet is plugged in, I have no problems accessing the server with ssh, imap, or viewing the webpage. However, if I unplug the ethernet cable and use the wireless it sometimes works and sometimes does not.

When it is not working, my mail application won't connect to the mail server, I can't view the webpage, and tonight for the first time I also couldn't ssh into the server (I got the following error- ssh_exchange_identification: read: Connection reset by peer). I can still ping the server without any packet loss no matter what, but everything else doesn't work. What is so confusing to me is that it sometimes does work just fine without changing any settings (in fact it has started working again while writing this post). When it is not working I still have internet access and can reach the Webpage using a proxy server (Proxify) and if I plug in the ethernet then everything works as intended.

Another part of my set up that may or may not have an effect on this is that my server is connected wirelessly through WDS to my router.

While it is an inconvenience for me, it is a show stopper for my wife since she can't access her email when this happens and I am away from the house.

I would really like to understand what is going on instead of just finding a workaround and never knowing why it is working. Any help would be greatly appreciated. Thank you