i think that resetting the database user(s) to match the login is the backwards way to do it; you have to re-do it with every restore.
i prefer to script out the user from , say production via sp_help_revlogin or something similar, so you have the sid, and drop and recreate the sql login on dev, then change the password on dev.
then the sids ALWAYS match, forever, and tno subsequent restores form production suffer from orphans any more.
--help us help you! If you post a question, make sure you include a CREATE TABLE... statement and INSERT INTO... statement into that table to give the volunteers here representative data. with your description of the problem, we can provide a tested, verifiable solution to your question! asking the question the right way gets you a tested answer the fastest way possible!