I used to have the same problem and it seems I have found a solution. Change your DNS settings to OpenDNS. My experience is that it is better to do it in your computers and not in your router. I had to stop playing live chess because I had terrible lag and got disconnected a lot (which could result in closing my account). I haven`t had a problem with live chess since I set opendns as my primary one - well, I will play computers only for a couple of weeks for if I get disconnected there will be no poor soul waiting for my move.
You should be able to change your settings easily for everything is explained and shown on the site (see the link above). It is really free and no adware, malware, and other annoying stuff comes with it. But if you have a problem do not hesitate to ask me.
I keep having some trouble with my Internet. Every now and then, both of my computers will get this random error, and no browser or website becomes accessible due to this error message:
Error 105 (net::ERR_NAME_NOT_RESOLVED): Unable to resolve the server's DNS address.
Strangely enough, my Internet signal is fine! Nothing seems out of the ordinary, and resetting my wireless adapter (because the useless Windows advice recommends that) doesn't do anything. I have to wait for it to get back to normal, which can take any time from two minutes to an unknown amount of time -- I waited over an hour, then gave up and went to bed.
Some advice on this problem would be extremely appreciated!