Custom Membership Provider and "standard" Role Provider

Hi All,
I have successfully built a custom membership provider.
Now... I had hoped to use my new custom membership provider along with the 'standard' role provider (not customized). So I set up my web.config file accordingly.
A quick look at the aspnet_UsersInRoles_AddUsersToRoles stored procedure made me realize that this isn't possible because it references the aspnet_Users table (obviously instead of my custom membership table dbo.User), and creates a new entry if a matching UserId isn't found in this table.
So I've understood that I have two options:
1 - Modify the standard stored procedures for the RoleProvider (aspnet_UsersInRoles_AddUsersToRoles etc.) to work with my custom membership provider tables (dbo.User)
2 - Or, create a custom role provider (which I wanted to avoid - mostly due to technical inexperience)
Option 1 seems the easiest but will it create problems elsewhere???
Am ...