Female Seeds??? or are they???

I have a huge problem with some plants.
It seems that the Femanized seeds I purchased have a couple beans sprouting out.
The two clones are from different mother plants yet there are 2-3 seed pods all together.
They are deffinatly male flowers and stand out like a soar thumb on the lowere couple branches.
Do plants become hermie or are they genetically pass over traits???
How did this happen???

females do make pollen sacks if stressed. Probably really small amounts of light leakage or unstable environment. I had it happen myself, ended up being small amounts of light leakage in my grow room