We have been running an 1841 router with one T1 interface and one FaE interface for over 1 year now with no problems. Recently we added a 2nd T1 interface and bonded it via multikink PPP with the 1st T1 interface. Almost immediately we started experiencing problems with access to the router via the FastEthernet interface. Bringing up the log on the router we see continuous messages claiming that "Fa0/0 changed stated to Up". Funny thing is that there is never any "Changed state to down" messages, all are up!! We changed the FaE interface to another switch port with no luck. We also played with the duplex and speed commands with no luck. The we decided to shut down the 2nd T1 and remove the multilink parameters and the interface and our problems went away. I know it doesn't make sense but is it possible that the multilink config was affecting the FA interface? At this point we have decided not to go back to multilink for now but it would be nice to know for future reference.