I have been on this problem for a while. I need to compare a paasword that the user enters to a password that is in the membership DB. The password is hashed and has a salt.
So much work! Microsoft makes life much easier with HashPasswordForStoringInConfigFile:
HashPasswordForStoringInConfigFile
string myhash = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(password + salt, "SHA1");