Cisco IP Phone Firmware Downgrade Issue

During a Cisco 7965G IP Phone install, I noticed that the phone would download the firmware from the Cisco Unified Communications Server (CUCM), but would not actually install the firmware. The 7965 had a newer load, 9.3(1)SR1, and I was attempting to downgrade to 9.2(3) because of the limitation of the Cisco Phone Designer software. After several reboots of the IP Phone and tinkering with the FTP Services on the CUCM, I proceeded to open a TAC case with Cisco to see if they could solve the issue. After three weeks of packet captures, CUCM log dumps, and even video recording the events, we discovered that the 7965 hardware version that I had (v14) only worked with 9.3(1)SR1 and above. This is clearly stated in the Release Notes for 9.3.(1)SR1, so it just goes to show, don't ignore the Release Notes.