[development] Users can't log in after creation

Hi, Im having the following senario on a production site with drupal 4.6 1 User creates an account 2 user get his e-mail with password 3 User tries to log in, but get's a user not found What is the problem. If the user waits 5-10 minuts, the user is able to log in. Any ideas? slow database? -- Best Regards René Madsen http://rene.schultzconsult.dk