Download speed

The geographic location from which your tests were performed would have a significant influence on the results.
I'm guessing you're at least one ocean away from either datacenter, so you should probably be looking at traceroute results rather than the approximate download speed your browser calculates if you want to know why one packet is taking longer to get to you than another. Network routes are neither static nor infallible, and I believe California was being hit by a DDoS attack earlier in the day.
strange I'm from fance and I reach my maximum speed with http and accelerators 1,2Mb/s but if I try with ftp one dl session it does not go over 200kb/s from france, I recommand using DownThemAll plugin if you are under firefox, powerfull downloader directly integrated in FF, very handy here to reach my real dl speed because i guess without I won't go over 200kb/s with one dl session, Im too far from the source I guess, http accelerators are nice workarounds