Slackware :: Failing To SSH Between Boxes On Same Wireless Network

I've got a Linksys WRT54G router with the latest firmware. I've got an HP laptop connecting wirelessly and my main box connecting wirelessly with a Linksys WMP54G card. (As an aside, I used to have another box too with the same wireless card). Both are set up with a static IP. Both can access the Internet just fine. The router is on the main floor. My main box is in the basement. Both boxes are running fully patched versions of Slackware64 13.1. sshd is running on both.

I like to ssh into the other box when there's a security update or to copy a file from one computer to the other, etc. The problem is that I can't do that all the time. Even if the laptop is connected to the network and accessing the Internet, on my main box ssh will still "say ssh: connect to host ***** port 22: No route to host". It is my understanding that if I ssh in, it is accessing the other computer directly and not going through the router. What would cause this? Even if I bring the laptop within four feet of my computer, it still can't connect.

There doesn't seem to be a rhyme or reason to when it will connect and when it wont. Sometimes I can access it just fine then about five minutes later I can't.