Effective Start Date problem

[tlange]

I have an SCD, set to keep the Effective Start Date at the day level.  It works fine unless I run it twice in the same day, as it ends up with this:

RECORD    EFF START     EFF END
1             10/20/2009    10/19/2009 
2             10/20/2009    NULL

Is there a way to make Data Manager recognize records with the same effective start date and just update the existing record?