On Feb 20, 2008, at 9:09 AM, Geoffrey wrote:

> "tract_order_num_key" unique, btree (order_num)
>
> So, this application has been running along just fine like this for  
> a couple of years.  Is it possible that the above index is causing  
> the problem?

slony won't care about this index.  all it cares is that you have a  
primary key defined for the table.  your above key does not qualify as  
a primary key.