We too have tried everything to get credit cards to swipe through to the desktop.  While Notepad shows that the card reader is actually reading the card, Quickbooks does not show the card as read.  I believe no solution is being provided because Intuit Merchant Services is benefiting from the error by being able to charge transactions higher fees because they are then required to be handkeyed.    

Further, the issue does not lie in the cardreader.  We have readers provided by QB and also from Amazon.  Neither readers will show a swipe in QB, but show the swiped information perfectly in Notepad.