The word which you're translation calls a "drop emitted", clearly refers to semen, not sperm. Sperm are small cells which swim in the liquid we call semen.

A simple search on wikipedia illustrates that semen is a mixture of several fluids, which are produced by different glands in the lower abdomen.

http://en.wikipedia.org/wiki/Semen

The testicles do produce the sperm, which is a part of the semen, but the fluids are produced by glands which lie deeper within the abdomen.

'between the back-bone and the ribs' indicates this area of the lower abdomen, and is therefor very accurate, and actually indicates that the writer of the Quran knew that semen was produced by more than one organ, giving an area rather than a specific location for its production.

I will look up those references you mentioned about a flat earth.