Ubercart

making a bunch of assumptions about your set up (versions, ssl and hosting provider) but most UPS errors are simply due to little mistakes in the configuration set up although in the forums a bunch of people have unfortunately resorted to swithcing their hosting due to server limitations

Make sure the current UPS module is installed and enabled, http://www.yoursite.com/admin/store should show a green check-mark next to UPS Online Tools under 'Status messages'

then go to http://www.yoursite.com/admin/store/settings/quotes/edit and check the first two boxes to see any error messages when trying to get a quote. you can uncheck the third box to allow orders go through without a quote, but then you'll have to workaround getting shipping paid for and manually process shipments with UPS online if you can't get it fixed. and make sure your default shipping location is correct

http://www.yoursite.com/admin/store/settings/quotes/methods and make sure the UPS method is checked. then go to the UPS settings and double check your access key is correct, your site is in production mode you've got the right services ticked and your account type is setup the way you need

as an admin put something in the cart and try to get a quote. the UPS server response should have your information displayed and the destination that you set. if you're not getting a server response or other errors check at http://www.yoursite.com/admin/reports/dblog to see if you have any errors related to quotes or UPS.

from what I've seen most problems are due to account details and/or access keys not entered correctly (they are case sensitive along with the passwords), cURL wasn't setup on the host or there were timeout and/or connection errors related to php settings or host server limits.

if you can't get it to work, try providing a bit more specific info and hopefully someone else can take you up on your offer