I had to enable netflow on an interface this morning to see what was taking all of our bandwidth. After finding the host, I created a class map to add to the already existing policy map that was on the serial interface. I wrote my changes, and then realized that I wanted to take netflow off. When I took it off, the router locked up and brought all of our branches down.
I've enabled/disabled netflow on many production networks and haven't had this happen. Can anyone think of a cause? Processor seemed to have been fine.