Thanks Carlo.So you are thinking that perhaps the port does not come up quickly enough following a reboot and this is why it would stop receiving input?  Do you believe that adding the spanning-tree now without a reboot will force the ports to start ...

Did you ever get a reply to this question?  I am having the same issue with two different pairs of Juniper IDP's connected to 3750E stacks with IOS version 15.0(1)SE2.  They were working fine then after a reboot, which was done to turn off the web se...