2003 impala won't crank, HELP!

[cvc]

my 2003 impala will not crank I checked the ignition switch and power is coming out as it should. The radio says locked which means that the security system is messed up. also, the security light comes on. The car will crank and start just fine one time after you disconnect the battery and let it sit over night. Onec you shut it off and try to start it again the starter does not even attempt to crank. The starter relay is not being engaged by the pcm, I know this because bypassing the relay will crank the car. The battery light is also on in the message center and the volt guage shows that the battery is at 8 volts. it is wrong. when i check the voltage with a volt meter the battery is at 12 volts and is charging at 14 volts. It is a serious pain to have to let the battery be disconnected overnight to make it start. Also, the transmission started shifting funny and the spedometer was not working right this happend intermitantly before i started having this problem, don't know if this has anything to do whith what is happening or not. Any help or ideas anyone has would be greatly appreciated!

[micali]

sounds like the ignition switch. I was told to replace the lock and cylinder and ignition switch.