Connection Speed Problems

Here is my issue:

I lived in the city. I had a powerusenet server that maxed out my connection at a 600kb/s speed. It never dipped below that for any extended period of time. If I visited my parents and tried to download something I would get a whopping 1000kb/s due to their higher speed. I loved it. But suddenly I would look at my download rate and I'd be getting at the most, half: 500kb/s. If I was lucky the d/l speed would increase again.

My dad said that the problem was due to his router failing. I said oh well.

Now the problem... I've since moved back in with the 'rents for a while. Because I couldn't stand to use a crappier D/L speed than what I could be getting here (1000kb/s) I swapped his "bad" router for my Apple Base Station which I knew to be working.

But the problem did not cease. Still I would begin a download at 1000kb/s and then find it drop to 400.

So I switched his modem with mine, too.

The problem remains! I am getting HALF the download speed than what I should and what I occasionally do. A speed test reveals that all is well, it marks my download speed at 14mB/s or so. But this does not reflect in my download speeds.

I called my ISP and asked them what might be wrong and he could not tell me.

So what's going on? Voodoo?

I've also tried two different usenet providers and both of them are staggered by 50%.

This exact set-up (modem, router, and laptop) only encounters this problem in this house.