OpsCenter just periodically calls describe_ring() on different nodes in the cluster, so that's how it's getting that information.
Maybe try running nodetool ring on each node in your cluster to make sure they all have the same view of the ring?
We have a 10 node cluster (v0.7.9) split into 2 datacenters. Three times we have seen nodes move themselves to different locations in the ring. In each case, the move unbalanced the ring. In one case a node moved to the opposite side of the ring.
Sometime after the first spontaneous move we started using Datastax OpsCenter. The next 2 moves showed up in its event log like:
5/20/2012 11:23am - Info - Host 126.96.36.199 moved from '12345' to '54321'
where '12345' and '54321' are the old and new tokens.
Anyone know whats causing this?