Scanner Problem

I have a Mustek 1200 III EP Scanner. When I plug the scanner in (power cord) my high speed internet slows to a crawl and sometimes the red lights on the DSL Modem come on and I have no internet connection at all. The power supply for the scanner gets very hot also. I tried changing the parrallel port setting from SPP to EPP which helped keep the DSL lights green, but connection very very slow. Anyone have any idea what could be causing this?

Thanks,

Ron