I have the exact same problem described below and while attempting to run the solution posted on that thread, I ended up losing my internet connection in Ubuntu.
i have an unstable internet connection,when browsing suddenly i'm unable to load anything which keeps going for a min or so then the internet comes back to repeat that again after a while,same for any other internet app. i have another os (windows 7) on the same computer and the internet works perfectly so i guess it's a system related thing,even when connecting to the same router by another computer at the same time (by wireless on the same router) everything works fine even in the moment ubuntu is not.
running:
sudo rmmod r8169
Internet is disabled and enabling it will not return connection.
sudo modprobe r8169- do you have a question that needs answering here? – Paul Jul 9 '12 at 12:41