If smartgrid is used to edit the values of fields in auth_user that are designated unique=True, smartgrid will crash when a duplicate value is entered. Here's a ticket trace. SQLite is the underlying db. Incidentally, this is my first go at grid and smartgrid and I'm very impressed. Kudos.
File "N:\web2py\gluon\sqlhtml.py", line 1962, in smartgrid user_signature=user_signature,**kwargs) File "N:\web2py\gluon\sqlhtml.py", line 1584, in grid next=referrer) File "N:\web2py\gluon\html.py", line 1951, in process self.validate(**kwargs) File "N:\web2py\gluon\html.py", line 1898, in validate if self.accepts(**kwargs): File "N:\web2py\gluon\sqlhtml.py", line 1265, in accepts self.table._db(self.table._id == self.record.id).update(**fields) File "N:\web2py\gluon\dal.py", line 6346, in update return self.db._adapter.update(tablename,self.query,fields) File "N:\web2py\gluon\dal.py", line 1093, in update self.execute(sql) File "N:\web2py\gluon\dal.py", line 1359, in execute return self.log_execute(*a, **b) File "N:\web2py\gluon\dal.py", line 1353, in log_execute ret = self.cursor.execute(*a, **b) IntegrityError: column username is not unique