mmonin: I have the exact same setup here, cable modem through a linksys router, and I had a very simlilar problem...pages wouldnt load sporadically, etc etc. It turned out that it wasnt a problem either with the modem or the router

I put up with it for a really long time, but then I realized I could never stay connected to any internet games, DoD, BF1942, etc, and that really pissed me off, so I called tech support for road runner (i also use road runner, here in austin texas) and said look, im getting sporadic disconnects without the modem going off or anything, so they sent a tech out to my site.

first thing: try a tracert next time you have that problem (go to MS-DOS prompt and say "tracert www.google.com" or whatever site, and watch where the trace starts timing out.

second thing: call tech support and insist they send a tech over to check out your line.

when i called they did a check to my address (you read off your MAC address on the modem, or give them you name/address) and theyll run a line check to your modem and check the signals. mine tested irregular, and I think yours will too, so they sent the tech out.

when he got here, he plugged his line meter straight into the cable line and said "holy ****, your signals...". turns out, the wiring in my house was total crap, and had been there for ages...the insulation was frayed off and everything. the line was so full of noise that although the modem would read "connected", packet loss was through the roof. long story short, they didnt know it was the wiring the first time, so they switched out some components in my cable box, and it didnt fix it, so i called back, and on the third technician, they just replaced the whole wire and SUPRISE it works fine. (while you're at it, make them give you the latest version of the cable modem...while it worked after they re-ran the wiring, having a new modem also helped cause it can deal better with the noise in the line). theyll give you the new modem for free if you bug them, and you trade it out.

for some reason they have a definition of acceptable packet loss, so what you can do is find the default gateway for your router (its on the status page of linksys setup) and ping it. do the following to impress the folk on the tech support line: at MS-DOS prompt, enter the following "ping (insert router's default gateway here) -t" and then let it run for a while. push ctrl-break occasionally and watch the percent packet loss. if its less than 3% they wont help ya. mine was reading 46%.

so yeah, give tech support a call, have them send a guy out to check your line, give you a new modem. it cant hurt, and i'll bet it'll solve your problem. hope this helps!

edit: they may not have to do something so drastic as replace your cable line...they can also adjust signal strength by toying with the splitter where it enters your house...different types produce different signal qualities.