I have the same problem.. Linksys ADSL2 gateway AG241 - Wired Modem/Router combo, Atheros L1 Gigabit Ethernet 10/100/1000
Driver, Dynamic IP (Automatic)
This has been going on since my Win 7 install on Sunday, and I can't find any fix either... If I try a Static IP, it Immediately disconnects.... Otherwise, with Dynamic IP, it disconnects every few minutes.. then on Sunday night after hours of fiddling around it finally stayed on the rest of the night... But next day after I got home from work and turn computer back on... Same Same as we say here in Thailand.
Now I have to reset the driver (Diagnose the connection) every 5 minutes or less, just to stay on and post this.
HELP... PLEASE !!!!!
CS