Atheros wireless card and Linksys router

I have a brand new Toshiba Satellite with an internal Atheros super G card. I was using a Linksys G speed router and a card in a 2 year old Toshiba with no problems (it is still working, btw) No matter how I set up the new laptop and it's internal card, it won't hold my connection. It sees my network which is secure and logs on then at the higher speed, it can't hold it and logs off. A technician came to the house and set up the atheros card to only go at "B" speed as we thought that might work, but it will alternately connect at 10 then at 110 and then bump itself off. I need this hooked to my home network. As I said, the prior setup with the Linksys card and router are working fine. I have downloaded a new driver from Toshiba for the card but it doesn't change it. I'm desperate for a work-around. Any and all help will be appreciated. Thanks