[How to join lines, create a solid object and fill with color?]

hello. great little vid. however, after doing that i thought successfully, it seems the new shape does not fill as expected. the top and bottom were two open halves drawn with the pen tool. i joined the points as in your vid. but, the right side is what happens when i flip the fill - only the bottom half is filled, however the object is a single object. when i looked closer and moved one of the joined points, there were actually 3 points sitting on top of each other - highly unexpected. 

 

https://www.dropbox.com/s/0dnsdtypi5awpo7/problem.png

 

maybe related - but, i have noticed sometimes when i option drag a group of objects, it makes 3 stacked copies of them. anyway - main problem is this fill after joining points. any ideas?

 

(and, minor note - would be cool if the imbed image tool in the forum supported dropbox public folders).