spaghetti squash problem

help....
it is my very first year of growing, i have an allotment, and a small veg patch and greenhouse in the garden. everything seems to be going ok, apart from my spaghetti squash, plenty of growth, no yellowing leaves or any signs of anything wrong, but i have no fruit forming, i have flowers on long stalks then once they have opened they die off and thats it. 
the squash are in my greenhouse, i was thinking of pollanation problens but its right by the door and other things that are further in ie peppers chillis have all got fruit forming.
any advice would be great. thanks
lisa x

Peppers and chillies don't need insects to pollinate them, whereas squashes do; if your plant has had both male and female flowers (at the same time!) then it could well be a pollination problem, in which case you can use a small artist's paintbrush to do the job manually.

the female flowers always have a very small squash behind the flowers, just waiting to be pollinated. If the stems are straight with no 'bump ' then they are males