subtracting statments

[Matt Williams]

I have two statements:
Select name from users
(this returns - user1, user2, user3)
Select name from installmatrix inner join
users on installmatrix.uid = users.uid where installmatrix.sid = 2
(this returns - user1, user3)

I want to subtract the 2nd from the 1st, so I use:
Select name from users where name not in
(Select name from installmatrix inner join
users on installmatrix.uid = users.uid where installmatrix.sid = 2)
(this should return user2, BUT I get a big fat sql error)

Pls Help!!! :)