I have an interface with the pause input counter incrementing often, I think. over 50 in 8 minutes. But I don't know for sure if this is a problem, the output interpreter doesn't say anything. Sounds like I'm oversubsribed? its an uplink to a 7204 router with an oc3 on it.
Possible, but I can not say for sure without knowing detail.
But one thing clear is that the router can not pass/handle the packets sending from the switch quickly.
If your serial line has issue such as flapping, it might cause your routing protocol flapping, As a result router is busy on routing reconvergence calculation...