Xbox 360 is crazy & downloads are canceled?

I wanted to download a few demos today, but when I have downloaded about 50-80 times the message comes up: "Can't be downloaded" on the memory can't be because 60 GB USB stick. But since the Wi-Fi was really, I connected them via a Wi-Fi amplifier. Can it be because of that?

Possible.
Our 360 is now quite old and often has these problems. I pushed it to old. If it is really used again, then via cable.