Wireless laptop disabling internet for wired computers

I have a wireless netgear router and a Motorolla Surfboard Cable Modem

4 computers connect via ethernet cable
2 computers connect wirelessly
and 4 devices (Printers, PDAs) also connect wirelessly

I am trying to introduce a new laptop into the mix, but for some reason when ever it connects all computers (not sure about devices) get disconnected from the internet until the router is reset. The network however never goes down. I am open to any ideas.

Thanks in advance for your help.