so I went shooting my 709 slim today and when i got home I took the gun apart and cleaned it, like i have done before. and i took the firing pin out and cleaned and lightly oiled it and then put it back in and then put the slide back together and put it back on the gun. well I pulled the trigger and herd the gun dry fire, i then pulled the trigger again and it won't dry fire in double action mode. unless i gently pull up on the slide and then it will fire every time. did i put something back together wrong? has anyone else had this problem? what's the deal.