I have researched this problem and have found mentions of it on this site along with many others, but none have a fullproof resolution.
The problem: I am trying to help someone who had a comcast technician setup wireless in their house. They used a netgear cg814wg wireless router and also some default security measures.
I fixed the security and brought up the additional 3 systems they had in the house and the connection seems to keep dropping when one of the people start gaming. There is no complaints 90% of the time, unless this person is gaming and it drops atleast once often more.
(since the router is a special version for ISPs you cannot upgrade the firmware)
Have you seen this issue and what would you suggest?