Well, maybe you were running a bunch of internet using programs at the time? Speedtest.net gives a better estimate than bandwidthplace.

No i closed everything down, i was just running Firefox with the bandwidth place site at the time.
That gives me the Speed that my router detects.

Which router do you have? Also test your speed at 3am your time in the morning then compare the difference.

I have a Linksys WAG54G think it's about 3-4 years old.
Just tried Bandwidth Place again just out of interest it came up double the speed compared to the last time i tested it.
800 kilobits per second
100 kilobytes per second
And Speedtest.net always detects roughly what my router shows for the Downstream (1.5mbps-2.0mbps) and Upstream rate (350kbps-500kbps) give or take 50kbps-100kbps.
Tested at 4pm British SummerTime
Will try to test as close as possible to 3am will probably be 2am most likely.