Network over a powerline adapter

I just purchased one of these yesterday. It set up great after I took the update. The way I have it hooked up is through a lan powerline adapter. When I hook it up close to my pc which is running win 7 64 bit, it streams the movie files without any glitches. As soon as I move the unit upstairs to my bedroom the movie files slow down and become choppy. Is this due to the large files over the network?   I was kind of hoping that I would not have to hook up an external hard drive to this unit. Any help would be greatly appreciated.

Thanks

Powerline connectivity is flaky and depends on your home wiring. The general rule of thumb is, the distance is inversely proportional to quality and speed of the connection. Sometimes it helps to try plugging into different wall sockets.

I have had poor experience with powerline adapter. Might work one day, but not the next. Like it was already mentioned, it depends on home wiring but also on what else is powered from the mains.