I planned to promote a secretary to a project administrator.

However, my boss (CTO) took me on one side and said "never hire a woman - she will always want time off to go to knitting classes".

(Since then she has done a distance learning degree and is now a semiconductor layout engineer, thus proving my belief that she had a lot to offer).

This is also the same boss who told me the key to successful management - it was to make sure that you (the boss) were the only person who had all the information.