SMC barricade g and timing out

Just a few things that can be checked, firstly in the routers settings look at the transfer speed of the router(not the connection speed) and see if it's set at 108MBPS, if so your wireless network cards on your pc's may only be able to connect at a maximum speed of 54MBPS, unless you have the latest 108 or 125MBPS g type cards. Secondly you should be able to check the wireless signal strength by the icon in your task bar or software you use, as if you have thick walls or objects in the line of the signal from router to pc's, the strength drops and can read low and therefore cause you to lose internet connection entirely. You can also try changing the channel at which the router runs, normally this is channel 2, but trying channel 11, which is the farthest away from appliance interference may give you better results, but both router and network card channel numbers will have to be changed.