WireLess access point dlink 2100ap

i have an dlink 2100ap in my organization. i have connected 4 computer to my access point, but i have two labtop (sony, toshiba) that they dont see ap. i dont know what should i do,
i have another ap that labtops can see that and it is configured as same as previous ap. but i dont know why my laptops didnt connect to this ap.
plaese help me

I run a wireless network that currently uses 14 of the DWL-2100 access points, the only time i've struck trouble with clients unable to see the access point is when i'm using channels 12 or 13, some laptops (particularly toshiba) use 'world cards' which are locked to 11 channels whether the country you're in allows 13 or not

thank you for your assistance