In Ubercart 1.x, we allowed users to alter the text on various buttons in different parts of the store. This was a fine idea at the time, but we discovered it actually makes it difficult to create a multilingual store in Ubercart. Translation modules need to be able to translate these sorts of text as they appear in the code, not as someone has set them in a settings form. To resolve this, we have begun removing these adjustable text settings from Ubercart, with the hope of eliminating all hindrances to multilingual store setup.
If you were using one of these settings before to alter the appearance of buttons and elements in your store, never fear! There is a better way! Other Drupal modules, like the core Locale module and contributed String Overrides module, allow you to translate these sorts of text from any Drupal module. We recommend you look into one of those solutions or look into having a module written for your site that alters the specific bits of text you need. (For example, if you really just want to change one button, the overhead of another module is not necessary... Drupal modules can alter the text on any form through the magical hook_form_alter()!)
Notice the title of this page indicates that only Some adjustable text has been modified. We'll need more patches like this one to do make this complete, and it's still not clear how textareas like the ones used for the checkout message settings should be addressed.