These problems are common occurrences in my home network which is using the Linksys WRT54G model router. I've had this for quite awhile, but it's always worked to my satisfaction.
I've been noticing quite a few times where I will get disconnected from the internet (on WiFi) and a quick reset of the router will usually fix this problem. I'm assuming the problem lies somewhere in the router itself, but I don't have a very suitable base of knowledge on networking to verify this assumption. Another, probably unrelated, problem I have commonly is when my PS3 powers on I lose internet connection on all devices in the house. The PS3 is connected by ethernet cable. I'm not sure if other wired connections are affected by this, but I do know all wireless connections are affected by this.
I've been noticing quite a few times where I will get disconnected from the internet (on WiFi) and a quick reset of the router will usually fix this problem. I'm assuming the problem lies somewhere in the router itself, but I don't have a very suitable base of knowledge on networking to verify this assumption. Another, probably unrelated, problem I have commonly is when my PS3 powers on I lose internet connection on all devices in the house. The PS3 is connected by ethernet cable. I'm not sure if other wired connections are affected by this, but I do know all wireless connections are affected by this.