I have a client with several 3500 switches. Every 1 or 2 months, the telnet services disables. Productions is not effected. Only problem is i can't telnet to the switch. This is happening to more then 20 switches in the network. And it is like a domino effect. The only way to get telnet back up and running is to reboot the switch.
I did see a high memory being utilized by the Http/https so I disabled it. The problem went away for some time but is back again.