hello, i have a question. Yesterday, my 4mb stremyx was getting 4.3 mbps on speedtest and the port is opened at  5120. torrent also worked fine, i got 400+ kbps. today suddenly my port speed drop to 3905 and speedtest only 3.4-3.6 mbps. torrent and megaupload is now down the drains (10 - 20 kbps)

is this normal? can anyone please tell me what is wrong with my internet?