Hi,
What version of mojoPortal are you running? You can determine this by clicking the Administration link and then clicking System Information in the Administration Menu.
If you are running a version of mojoPortal older than 2.3.3.9, you will be able to use Artisteer templates without a lot of work.
Also, if you are using Artisteer 2.4, you must have mojoPortal 2.3.4.1 or higher.
Thanks,
Joe D.