It sounds like you are knitting top down (I'm a toe up kind of person) but, the stitches that you bind off and the stitches that you pick up are different stitches.
Look at the video in the Free Video tab about on Working Heel flaps
(about 1/2 way down the page) it is under the advanced techniques of the free video. This will explain it better than I can.
The video section is a great place to look for answers, but, everyone on this forum is more than willing to help.
You may also want to stop over at Any Sock KAL II
we talk about everything including socks and there is a lot of knowledge in the group.
If you have any other questions after the video let me know.