We are experiencing this problem and have called QB multiple times - this has been an issue for MONTHS.  I've called multiple times asking for an update on the status of my ticket, but when I ask for details or to speak with a manager or someone who can provide a real update, customer care cannot connect me with anyone who has real information.  I have received no e-mail updates from QB regarding the progress on this issue - again, it is has been months.  I have cleared all caches on all browsers and have scrupulously gone through all clients contacts to check for spelling errors, etc.  I've also removed any BCC and CC to ensure there is no confusion.  When I check the sent/view history it seems to be showing "viewed" when it was ME who viewed the invoice, not the client.  I have sent separate e-mails to the same e-mail addresses through my regular e-mail application and they are all working properly through my normal application.  Yesterday I sat on the phone with a customer care specialist for 44 minutes trying to speak with a manager or get an update and she was not able to reach anyone to help us or provide an update on status.  The customer data page seems to have changed as well and is not as user friendly (perhaps there is a connection?).  I am tolerant, but this is beyond frustrating.