downloads very slow!

I used to run downloads very fast on and now all of a sudden, they got very slow. If i try to download a 40 MB file, it takes about 10 hours cause i only get 1-5 KB/S. I used to download those same addons and it would only take 3-5 minutes. The websites load up very fast, and runs fast, but when i try to download, it takes forever. Please help me!