Rake session problem

Im currently working through the pragmatic rails book and have come
unstuck when using the following command:

rake db:sessions:create

This command creates the rake file, which contains the code needed to
create the tables. But when i run rake db:migrate it seems to ignore
this step. If i try and force it to use this step (004) by using rake
db:migrate version=4 then it creates the table but not the tables for
the steps previous.

Ive had a read around and there seemed to be a problem with an earlier
version of the book, in that it listed the command rake
db:session:create (singular) but this isnt the problem im having?!?

Can anyone shed any light onto the situation?

Thanks