We have a virtual chassis with three 6860.  We have a link between the switch and one 6900 router. The problem is with the link aggregate LACP. The link combine the 1/1/28 port and the 3/1/52 port at the switch. My problem is when we lost the link aggregate because one power off at the router for example, the aggregate on the 1/1/28 remains down when recovers the power at the router. The other one, 3/1/52 is up. The switch ID 1 recognize the Mgbic (1 Gb SX) but the laser is off. I have to reboot the virtual chassis to recover the link at the LACP.