DSL problem?

at home I have a DSL Speedstream modem from AT&T and a linksys router that I use to connect both my computer and my wife's computer and am constantly losing the internet connection between both computers. I then have to go into the router page at 192.168.1.1 and re-enter my password a few times then sometimes it will reconnect and other times the DSL light will flash for several minutes and then go red and I have to turn the modem off and back on. This happens at least 10 times a day and is annoying as hell. I've talked to Linksys customer support and they say the router is working fine, and had AT&T come out and they say everything seems fine to them. This same thing happened about a year ago and AT&T replaced the modem and it worked good for a while, now the same stuff. Anyone have any ideas? I was thinking the modem went bad again, but they didn't want to replace it this time.

adjust the MTU's to a lower number below 1400....

thanks, I'll give that a shot. any suggestions on what I should lower it to? I know nothing about this kind of stuff.

use one device at a time to see which is the problem.

stephen

they told me to lower the MTU to 1400 and had me upgrade the firmware on the router after I continued to have the same problem. currently I have the modem set on bridge mode? they told me to unbridge the modem and see if I have problems bypassing the router. any idea how to unbridge the modem?

no, they pretty much suck and were very difficult to understand. I remember they initially had me set it to bridge by going to like 192.168.0.1 or something like that (there's a sticker on the bottom of the modem that has that info) but when I try to go back in that way I get the "page can not be displayed" screen. the "dsl" on the modem seems to blink and then go red a lot. sometimes turning the modem off and then back on will fix it temporarily. which kind of makes me think the modem is jacked up moreso that the router but my knowledge of this stuff is pretty limited. could a bad router made the modem lose connection too? when this light does blink like that I can hear like a static noise over the phoneline if that makes any sense.