[c-nsp] Spanning-tree problem

[Renelson Panosky]

I have three 6509-E daisy chain together i know that's not the best design
but it was working fine until this morning.
for some reason the second switch took over as the root bridge
i changed the spanning tree cost to a higher number and it still claiming to
be the bridge.
i do a sho mac-address-table | include the mac-address i can't find it
can any one please help ?