If a prior PB operation times out, a late-arriving answer can trigger default clause handle_info() error log spam, e.g.
2012-10-21 01:44:14.250 [error] <0.31976.2002>@riak_api_pb_server:handle_info:170 Unrecognized message {51911707,{ok,{r_object,<<"bucket">>, ....
We've a customer who's had intra-cluster communication problems (including busy_dist_port warnings) where 40 or more of these messages would be logged per second.