96,97d93
<                 unique_value = klass.find(:first, :order => "#{s} DESC").send(s).next
<                 
99c95
<                 object.send("#{s}=", existing.send(s).nil? ? 1 : unique_value)
---
>                 object.send("#{s}=", existing.send(s).nil? ? 1 : existing.send(s).next)