man o man do I love cast iron.
I learned to cook in my great grandmothers skillet (I have an old panotype picture with the thing on the fire!)
Hopefully you really washed it out well with soap to remove the machine oils. I typically will wash it, boil it to remove residue, place it on my BBQ with a heavy canola film and bake it for several hours (no need to worry about the smoke outside!) I re apply the canola several times during the hot cure. One thing to remember is that sometimes there is a wax film on the cast iron if it is coming from overseas!
Then I cook. Never had a problem with my ton of Cast iron skillets, dutch ovens and griddles. Just be sure to clean with water or oil and salt mixes only - no soap after the first washing.
Good luck with the Iron