However the regs are as I posted, or at least I believe they are. In response to QNH's question I looked in the trusty VFR flight guide, and thats what I printed.
I am not sure this is correct. As I understand it, you may be on top of 8/8 provided you can meet the fix requirements - every 30mins if by visual reference and 120mins if by radio aid. The 4/8 comes as it is a given that you cannot get a positive visual fix if the cloud is more than 4/8. Therefore, flying over 8/8 for 20mins is ok - not sure how you know its only 20mins of 8/8 but that's another question.