Asus A7N8X Help!?!

has anyone that owns this board ever had problems with the onboard NIC? I use an asus a7n8x deluxe (2.0). It's been great until lately, both of the two NIC's are giving me trouble when I'm online. I loose connection between them and my modem. I've tried everything, unplugging my modem, uninstall-re-installing drivers, updating drivers, updating bios...etc. I have literally thought of everything. Are onboard NIC's generally know as crap? I went inside my bios and disabled one of the two NIC's (the Nforce one, I left the 3com on) And I still get the same problem. I've had technicans come to my house to check the internet line (cable modem) ...etc.