Product Variations missing from eCommerce configuration

Sorry for the stupid question but Drupal is relatively new to me.
I'm trying to help a friend out. Installed Drupal 5 eCommerce and ec
subproducts to try to add variations to a product type (ex. he sells
manuals in print and electronic form. He wants his customers to be able
to choose which option they want before checkout). For some reason Product variations is not
listed in eCommerce configurations as it should be so I am at a
standstill at this point.
Any idea why this is missing and/or how to add this feature????
Any assistance would be greatly appreciated.
Thank you.

Tracey