On a 3825 with 4 hwic-4t1/e1 cards all is working well until we add a 4th or 4th and 5th line to our MPLS multilink bundle. We have 5 circuits, and any combination of 3 runs reliably. When we add another circuit the connection destablized resulting in route flapping on the entire network. We have 5 circuits bundled in two other locations on 2811s with 2 port cards. Only this router is having trouble.
I have this problem too.