Also, regarding the "heavy load disconnections", are you using P2P software (such as Azureus or another BitTorrent client)?
If so, make sure you limit the upload speed within the P2P client (perhaps to half of your actual upload speed), & also reduce the number of connections.
My old WRT54G used to fall over under heavy BT use, if I didn't cut the speed & connections.
Oh, &

btw