any one else's pumpkins going bad

Had a similar problem with some of my squash  this year with the flowers and small fruit rotting. I read that water (rain) in the female flower can prevent pollination by preventing pollen sticking to the female flower. This tallied with the fact that only my vine plants have been struggling but my bush squash, which have a canopy of leaves stopping rain entering the female flowers, were producing loads of fruit.
I have had some success by putting cut off plastic bottles over the female flowers just before they open to keep out the rain and manually pollinating  when they do open(usually using bush plant male flowers which are also dry and not full of rainwater). This appears to work as flowers treated like this usually set fruit whereas those I don't protect still usually don't.
Hope this is worth a go even though it's getting late in the year for getting big pumpkins.
Jon

I have 3 pumpkin plants grown from seed in a large pot and 1 lovely orange pumpkin on each about the size of footballs. I had lots of smaller ones which looked like they were going to get big but shrivelled and died, now all the leaves have a white mould appearing on them? now the fruit is orange can i pick them or do i have to wait?  :?