Another digital tacho question

Deepinvet:
I’ve just had a another quick lok at the VOSA regs (revised 2007) and you are correct.
But they do slightly contradict them selves buy saying under the heading ‘Breaks’… After a driving period of no more than 4.5 hours, a driver must immediately take a break of at least 45 mins, unless he takes a rest period. A break taken in this way must not be interupted.

There is no contradiction. If you have done the first period as 4.5 hours driving without a break then you must take a full 45 minute break at that point and cannot interrupt it. At the end of the 45 minutes you have another full 4.5 hour period available before a break is required. If you drive for 2 hours, take 15 minutes, drive for 2.5 hours and take 30 minutes break, at the end of the 30 minutes you will have 4.5 hours available before another break is required.