Adding new users

I’m having issues with adding new users: my developer has advised me is a wordpress 3.1 issue.
When I’m in a subsite (as superadmin most of the time, so that could be the problem) and add a new user, it sends them a confirmation email but when they click on it it takes them to the subsite front page, not to a login screen.
My dev told me I need to add them as a new user in network admin, then add them the existing user to the subsite from within the subsite admin.
This is very cumbersome.
And by the time I notice it, it won’t let me re-add them for a few days because an invitation has already been sent, so I need to contact them and send it to a different email.
Is there a way to directly add new users to the site?