I've attached an archive of all .po files of ubercart package.
The phrase "Receiving Quotes" appearing on checkout screen is placed into this js fie:
you have to translate by hand and reupload the file shipping/uc_quote/uc_quote.js on your website.
Please consider uc_paypal.zip for paypal module (i've changed some strings)
there are still some mistakes into this translation..
as soon as possible i'll upload a new translation updated to alpha8