According to the docs when you validate on uniqueness it is supposed to skip the check on the column. I am getting failed validation on updates for some reason. Rails 2.3.5
Please provide more information about (or just check) your migration and model and its associations.
In the meantime, ActiveRecord skips the check on the record/row (not the column) on Update. Here's the relevant text: "When the record is created, a check is performed to make sure that no record exists in the database with the given value for the specified attribute (that maps to a column). When the record is updated, the same check is made but disregarding the record itself. "
Have you verified your data, that there is only one record in the table with that value?
D.