Pacman,
Just for the fun of it, see if the 721 has a 3 prong electrical cord. If it does, you might want to try and lift the ground and see if that helps your DSL. Get one of those cheap little 2 prong to 3 prong adaptors.
I am wondering if there is some sort of strange ground loop problem that is causing problems with your DSL router. I would go in steps.
Check the dsl speed.
With the 721 unplugged from everything(Dish, TV, anything else) plug the 721 into the phone line, check the dsl speed
Lift the ground on the 721 and plug it in, check the dsl speed. If it doesn't go down, you have your culprit. If the speed stays the same, plug other things into the 721, checking the speed each time until you find the one that drops the speed.
Would make for an interesting experiment, should take too long and should only cost a buck or so
Just for the fun of it, see if the 721 has a 3 prong electrical cord. If it does, you might want to try and lift the ground and see if that helps your DSL. Get one of those cheap little 2 prong to 3 prong adaptors.
I am wondering if there is some sort of strange ground loop problem that is causing problems with your DSL router. I would go in steps.
Check the dsl speed.
With the 721 unplugged from everything(Dish, TV, anything else) plug the 721 into the phone line, check the dsl speed
Lift the ground on the 721 and plug it in, check the dsl speed. If it doesn't go down, you have your culprit. If the speed stays the same, plug other things into the 721, checking the speed each time until you find the one that drops the speed.
Would make for an interesting experiment, should take too long and should only cost a buck or so