@makfor49: Your installation is seriously messed up. You should wipe it clean and start over.

"Ubercart" is a collection of modules which includes uc_cart and uc_attribute. You cannot download Ubercart without getting those two modules - they are part of the download - and you cannot install Ubercart without those modules present.

Recurring Payments API and Recurring Product Fees are not part of Ubercart, and Ubercart does not try to use them, so you clearly have some modules other than Ubercart on your server that you're trying to use.

You don't say what the error is and where you see it, so it's hard to know what you think the problem is. The text starting with "Requires:" that you quote shows up to every module at admin/build/modules and lists the requirements for each particular module. You don't say which module is complaining that uc_cart is missing.

Perhaps you have some Drupal 6.x contributed modules that you've downloaded on a Drupal 7.x site? And make sure you only have one version of Ubercart on your disk - you can't keep multiple versions around and just "use" one - Drupal will find all the modules you have downloaded and if you have mixed multiple versions Drupal will be confused.