I have my ethernet cable hooked up to a WNDR3400 router, and my internet connection will drop for an instant randomly (usually happens at least once every 5 minutes) it then instantly reconnects. The problem is that when i'm downloading stuff, the disconnection will cause the download to fail and i'll have to restart from the beginning (making larger files impossible to download).
Also, I have an xbox in the same room connected to the router via wireless. It also has the same issues of dropping and reconnecting and that causes me to get kicked out of live.
Interestingly enough, my laptop, connected to the internet via wireless does not experience this issue when used in (or outside of) the room.
I'm 100% sure this isn't a problem with my desktop.