Manually adding a ASP.Membership account for an install script

Hello,

I am having issues with manually creating a membership user using the
stored procedure: aspnet_Membership_CreateUser

I can't seem to be able to insert a 'password salt' value and have it
work when I try and log in.

Here is what I did: After creating a user and being able to
successfully log into my application, I looked in the database for the
Password Salt.

I then used that SAME value along with username in my install.sql
script file (it just preloads the database with data).

My login doesn't work though, what could the problem be?
.