My problem was that i tried to pass the second exam right after passing the first one OCA exam(which is really easy).
I prepared for two weeks, that is definitely not enough for passing this exam! it's really tough. Next time i will take MUCH MORE prep.
I read oracle tutorial for 1z0-804, re-read summary for all K&B chapters , Enthuware 1z0-804 mock tests and Java 7 new features cookbook. I'm a mac user and we have some issues with JDK 7 so i didn't install it and tried to learn all new features of it from the books. THAT WAS DEFINITELY WRONG! There were a lot of questions about project Coin not covered in books! Next time i will write a lot of code using java 7.
Shame on me and wish me a good luck next time(i'm going to pass the exam in December)!