Five 9's Uptime
That's odd - some of BT's literature claims five 9's uptime, a quick Google finds one example:
"the solution is hosted in the core of BT's network with 99.999% availability"
Or just a few minutes a year.. Seems they broke that promise for many customers yesterday alone off just one faulty piece of kit. Hopefully they'll change such documents to 99.95% now! :-D