BT Option 1 Throttle

Does anyone know BT policy on throttling for option1, when it starts / stops, time periods, what it throttles ??

I was told by BT that they dont throttle when you reach your 10gb month limit but im certain they are doing some kind of throttling.

I use it during office hours and think I have been throttled down to 200kbps for basic internet access. (seems to return to normal after month end.

Most interesting thing happened today - logged on at 2mbps (highest for weeks), started up itunes which then started its podcast updates, internet went back down to 200kbps within seconds.
any thoughts ???

When I was throttled on Option 3 for going over, the throttle started the following month. The throttle period is between 5pm and 12am (restricted to 1Mb max) for a minimum of 30 days (as far as I remember it was 1 calendar month). If you do go over again while being throttled you will again be throttled for another month etc

Two types of throttle with BT Total

1. Going over the bundled usage limit
2. Traffic management that applies to all, no matter how little or how much they have used