door latch help needed

[msaintg]

hi guys,
I need your help. I finally got my doors to close properly, but now I can't get them to latch properly. The stock door latches do not seem to 'cam' over and catch the striker plate. The tiny 'lock' tab/pin is the only thing that holds the door closed. If I use the outside handle to open the doors, the lock pin pulls up and the door opens, but the pin will not come back down and the door no longer 'latches'. Do I have the striker plates upside down or something? I can't figure out what the 'cam' mechanism does.

I know, I know, i should have just bit the bullet and got the easy latches, but I thought the stock latches would work for a while so I could put my money somewhere else.

thanks,