Sex Starved Pumpkins

Although the pumpkin plants in my garden are huge they keep producing little baby pumpkins that just fall when about the size of a tennis ball.

A friend of mine has suggested it is casued by the fact that they have not germinated. The cure?

Get a flower (that has no bulge under it)
Wipe the stamen over the flowers on top of the little pumpkins

I have now tried this - wait and see I guess!