I am running a 3524 switch with c3500XL-c3h2s-mz-120.5-XU.bin IOS loaded. I was backing up the config using Solarwinds Cirrus Config manage with Cisco ACS AAA credentitals. Everything worked fine and then stopped. I can no longer log into the switch with my AAA credentials and have to access it with a local username and enable. I checked the config and nothing changed. It was previously running the same code but XW release but a code change did not help. Neither did a switch reboot. This happended to one other 3524 which all of a sudden start authentication to AAA after about a week of failure. My ACS server is working fine with 100+ device authentication successfully. What is up with the 3524? Debug logs for AAA don't show any useful except a failure for authentication which I already know. I have other 3542 switches with no problems.