Don't give up! There's seasoning and then there's seasoning.
I used to "season" my
cast iron pan all the time in the oven, with vegetable oil or shortening, and it was not very non-stick.
I solved this by making sure the fat polymerizes (see
Paul's cast iron article) when I season my cast iron. Here's a short how to.
First, remove any carmelized sugar from your yummy bacon, or whatever, and remove any sticky, un-polymerized vegetable oil. I had lots of this. Boil water in the pan and use a good, metal spatula and you'll get it off. (Don't be a dork and use a plastic spatula like I did; it simply doesn't work.) Trust this, you need to get rid of the sticky, to make the non-stick stuff work. Dry the pan well. Use a wet scouring pad if needed to remove any remaining sticky. Dry thoroughly again.
Second, apply a small amount of shortening, lard or bacon grease, and rub it into the pan. (Most vegetable oil does not work well for this.) You don't need a lot. Put the pan on the burner and heat on medium-high or high heat until the fat polymerizes. It's polymerizing when it starts to smoke and makes a spidery or blotchy pattern in the bottom of the pan. Turn off burner.
Third, repeat the second step after or before each use and you will very quickly - in one or two treatments - have a virtually non-stick pan. Once it's non-stick, (depending on how and what you cook) you will want to repeat the second step only occasionally and you can repeat the first and second steps as needed.
Voila! The secret is in getting off the sticky, using a metal spatula (d'oh!) and getting the spidery-looking polymerizing action.