Problem Solved
Allright, here it goes. As I previously stated in the first posting on this thread, I downloaded the current firmware update. It was a disaster! 24 hours later I'm better off than before I started with the download.
Thanks to the help of many members, my problem is solved and my 436 ~ 536 is working better than ever.
First; Changed the threshold mode from auto to manual. Verified the theshold level at 8. Changed the modulation to NFM,
The scanners have not worked this well since I purchased them.
Just a reminder to everyone, this worked for a P-25 system.
Thank you to everyone involved with this thread.