AirPort connection timing

Having been left without a working LAN port I'm now forced to use AirPort as my only network connection and have run into an intermittent but frequent problem.

The problem is connecting to my iMac remotely. If I set my machine to boot and shutdown on a daily schedule I can't access it remotely 80% to 90% of the time. Whether using the remote access software or ssh the machine just doesn't seem to be connected to the router most days.

If I leave the machine powered on all the time then I still seem to lose access at some point but without the reboot can't get remote access back without going to the machine.

I'm assuming that the problem may have something to do with the timing of the AirPort connection relative to something else. Is there any way to prioritise it to make it consistently available? Or does anyone have any ideas on other potential causes?

What version of OSX are you using?
Are all software updates installed?
Is your routers wireless security using WEP or WPA?
Have you tried changing the channel your router uses?
Do you have other wifi devices? Do they maintain a connection to the router OK?
Do you lose wifi connection when sat in front of the iMac using it or from a cold boot or just after it's been woken on a schedule?

Thanks for the reply.

I'm using Snow Leopard with all available updates installed

Router security is WPA

I haven't tried changing the channel because signal strength is excellent (the router is within 20cm of the iMac) and there is no interference (there appear to be no other wireless networks available within about 75m of my house)

I have 2 mobile devices (a laptop and a handheld device) which connect wirelessly with no problems. The iMac is the only device connected at the time I have problems (ie when I am not in the house).

I never lose connection when using the iMac locally whether it has been connected for some time or just booted. Of course when I am using it locally I am logged in. Using it remotely it would be in a pre-login state for the first connection each day. Also if I am unable to connect remotely, when I get back to the house and log in I appear to be connected without problem (whether the connection is made as I log in I can't tell).

What do you use to connect remotely?

What happened to the LAN port?

If you move the router away from the iMac does the issue improve?

I usually use Logmein for remote access, but as I mentioned in my first post, ssh doesn't seem to work either

The LAN port was fried in a thunder storm, but that's another story (and another thread)

The relative position of the machine and router make no difference. I'm confident it is not a signal problem.

Embarrassing confession time.

I think I've just found the problem. The LAN port was set up with a fixed IP address but I've just realised the AirPort was using DHCP so it looks as if port forwarding was working when it had the same IP address assigned. Loss of connection without a reboot may have been caused by change in IP address after a router reboot following a firmware update pushed out by my ISP.

That should have been one of the first things I checked