Unfortunately I don't think people realize what an ass they can be until its too late. I have the same type of situation w/ my biological father. Who by the way thought my wedding would be the proper place to bring up unresolved issues - nice, huh?
In my situation, I've chosen to be the bigger person. I keep up the communication because I didn't chose him, he IS my father, and life is too short to sweat the stupid sh**! Even though he rarely reciprocates communication when I need it most, in the end I will never feel that our relationship problems were due to my own failure to try and work it out. Hang in there - you're not alone
"Excuse me while I kiss the sky..." - Jimi Hendrix