When you say "won't be able to see the AP", does that mean:
- The SSID is invisible in "scan for networks" or similar SSID display?
- The SSID is found, but the client cannot get a DHCP address?
- The SSID is found, the client has an existing DHCP address, but cannot see the rest of the router, rest of LAN, or internet?
- The AP has gone invisible and you can see right through it.
If #4, there's a Nobel Prize waiting for you.
Please don't use pins. Voodoo is not supported by most access points.
Yep. What's your DHCP lease time? See Advanced -> DHCP as in:
- Don't have enough DHCP assignable addresses for the 9 clients.
- Have too short a lease time so that the router expires the lease overnight. When the laptop arrives in the morning, it tries to get a new DHCP assigned IP address, and either fails, or keeps trying to use the old IP address.
- If the clients are laptops that were taken home and used on a different wireless access point, it may have the home configuration saved. I've dealt with belligerent XP SP1 machines that will not automatically release the old IP address. I have to resort to: ipconfig /release ipconfig /renew to force the client to let go of the old IP and ask for a new one. This is especially a problem if you put the laptop in standby (power save, hibernate, whatever) instead of doing a full shutdown.
As I indicated, I'm not sure of the exact problem, but methinks it has to do with DHCP. I suggest a much longer lease time of 86,400 (one day) or larger.
If that doesn't work, I suggest taking advantage of the static DHCP assignment feature, where you pre-assign an IP address to each client, without resorting to static IP's.