MD5(MD5(pw)) OK?

Hi.

I am thinking about building a login, where the logged in users are
stored in a table logins. To make it shure and documented the users have
entered a password I want to store the MD5(pw) in logins. To make it
impossible to fake logins entries I plan to store the MD5(MD5(pw)) in
the users table and use this for authentication purposes.

This seems like a good idea to me. Does anybody see any flaws?

Thx,
Joachim

--
"... ein Geschlecht erfinderischer Zwerge, die fuer alles gemietet werden
koennen."                            - Bertolt Brecht - Leben des Galilei