Sweet pepper woes

Could you be watering them too much? In my (limited) experience, peppers only need watering when the compost or soil has nearly dried out, they hate too much water.

Also check for holes and a maggot inside.

Looking on the bright side at least you have peppers - The ones here seem to have been the same size and shape since May 

You need to aim for consistently moist rather than either of the extremes - it's that what upsets the little darlings' delicate little calcium constitutions. 

Lardman - I know what you mean - my bell peppers were sown much later than yours but romped away, setting flowers right, left and centre, but they now seem to have aborted many of them, and now have just 3 or 4 not-very-large peppers each. They always seem to promise to deliver far more than they actually do, but I still like growing them for their novelty value.