Hello Rick,
please use the Replication Server Area for these kind of questions, there you will find more details about RS.
SAP Replication Server -> http://scn.sap.com/community/sybase-replication-server
As Mark already mentioned a good idea to avoid these 5185 errors is to use dsi_row_count_validation to off or if you cannot use this or still want the 5185 messages in the log, you can ignore the error 5185 in your error class.
In both case be sure that these 5185 messages are errors you can ignore.
"but Sybase told me some 5185's may represent a real issue, not just a duplicate row deleted" -> Of course this can be a real issue, but this depends on how the database and applications are working. Can you say that no action is done on the WS side ? If so, you should verify why there is a row count mismatch. Normally all these 5185 messages do have an explanation and should be checked, to be sure.
I would suggest that you open a ticket if you like, so you get some assistance from Support to do the followup on this.
Hope this will help.
With kind regards
Stefan