CreateUserWizard cancel create user?

I use the CreateUserWizard to create users in my site.

I have an extra table in the database to save name, last name, telephone, etc. (I don't use standard method for extra information, I save them in my own table with the userID as PK that CreateUserWizard created for me.

In the CreatedUser event, I retrieve the user like this:
  CreateUserWizard cuw = (CreateUserWizard)sender; MembershipUser user = Membership.GetUser(cuw.UserName);
Then I save the extra data (name, lastname, telephone, etc) with my custom method using the user retrieved.
My problem is, if there is a problem in the middle of this code  (for example, lost database connection or any error), I would have something missing, because the user is already created and the extra information is not saved in the database.

It seems I can't ...