I too would use bottled water and see if it works. Or check your vinegar, sometimes depending on what vinegar you use it affects the flavor of the poached egg. And don't use too much, I hate it when my eggs benedict come out out smelling like vinegar. Bad!
Oh and by the way, you shouldn't be putting a wet poached egg on an english muffin. First place it on a paper towel, it will absorb the excess water and then place it on the muffin.