Broadband bandwidth usage - large drop in users at 08:30

[#1]

There is a large drop off of users on the "Number of customers using the network" graph at 8:30.
Hope it's a graph fault and not real!
http://portal.plus.net/support/service/network_performance/broadband_bandwidth_usage.shtml

[#2]

The rightmost edge of that graph often looks like that. But the current number of users on each gateway at about 43k all look normal. Not the same as sometime like this when the number of users on ptn-ag02 dropped to 13k.

[#3]

Thought it might be just a glitch with the reporting tool.