I have recently upgraded from 512Kbps to 1Mbps. On speedtest.net I get 1Mbps only with Wateen's server; almost all other servers don't take me beyond 512kbps. I have verified at different off-peak times as well with the same results. Similarly torrents max out at 512Kbps. All this make me think that within Wateen's network I am at 1Mbps but I am yet capped at 512Kbps for rest of the world. I asked their support and they said there isn't anything like that and I should clear up my browser's cache :-)
What are your speed test results who have 1Mbps connection?