I do not think that monthly figures mean anything really. They just make copy for newspapers...

One can draw conclusions from year on year figures though. According to Land Registry, London-wide there was a 5% annual increase in Q3 2011. Lewisham was more like 7% and some boroughs had a drop in the same period.

AFAICT, property values locally do seem to be still rising since the tube arrival even allowing for inflation. This is quite distinct from how many sales are occurring, though of course one can have an influence on the other.