by loren_d_c » Sat Jul 10, 2010 9:44 pm
Go to Preferences -> Store Text -> Receipts and replace the text for the 'This store is powered by ShopSite web catalog software.' setting with an blank space character (must have the space, just deleting the text and not leaving a space will cause the default text to still be used), or replace it with your own text.
-Loren