when I am logged into freenode channels on the Firefox extension "Chatzilla," on my Ubuntu-Studio 1204 on HP dv6000 laptop with 4 GB ram.
It has a RTL8101E/RTL8102E PCI Express Fast Ethernet controller
My first feeling was that "Comcast was throttling IRC!" which turned out to be incorrect. I brought my work (Windows 7) laptop home and it had no issues keeping the IRC channel connected for an entire day.
I am thinking there must be a time-out setting somewhere.