Another giveaway is the ethernet stats page in the subscriber module management. I have found that often when I have connection problems involving bad cabling it is belied by high inErrors and outErrors. These are usually CarSenseLost. In a good ethernet connecion you shouldn’t see any errors. I would imagine that a bad SS would also cause these types of errors and so would be visible without a truck-roll.
I am also experiencing a similar problem though with an SM that shows none of these errors so… I guess I will try the rest of the suggestions here. thanks!