I have this same problem. When I'm using my 10 Mbit connection, I only get about 600-800 KB/s. I should be getting 1.5 MB/s. When I'm on my 10/100 I get around 1.5-2.5 MB/s when it should be closer to 12.5 MB/s. I've never really bothered to look into the issue, but perhaps I should actually put some effort into finding out what is the problem.