QuickBooks Point of Sale (POS) will not print the receipts properly when using the Generic / Text Only printer driver. Instead, you will need to download and install the VENDOR THERMAL PRINTER driver from the article linked below.
In addition, there are steps needed in QuickBooks POS, which Intuit details in their knowledgebase:
http://support.quickbooks.intuit.com/support/articles/SLN43770
http://support.quickbooks.intuit.com/support/articles/SLN43770