Radio Installation Problem

Ok, So I am installing a new head unit into my friends 99 jetta, I have some experience in installing them, I have done it in my acura intergra my sis' honda accord and my dads chrysler sebring. Anyways, I had everything running properly and I was place the head unit into the slot and before hand I had to shove the wires down into different crevaces in the back. After I had the wires pushed back I started to push the head unit in, and well it was almost in and I gave it one final push and when it finally clicks into place the light flashes in the car...and I am thinking O' crap cause I forgot to take the lead off the car battery. When I test it with the head unit still in it would not start...when I pull it out the wires for the power had disconnected. I reconnected them and then tested the head unit again, it would not start. :banghead: I checked the fuses and they all seem fine. Anyone have any ideas of what could the problem be? I would appreciate the advice and help.