I have found success with printing outside the printable area using the Deskjet 990c drivers. Before changing your current print driver, do ensure you are using the Full Feature Software and Drivers for the Deskjet 2050 J510a (link is for Windows 7 64-bit US version). One way to know is to go into your Devices and Printers folder and the printer's icon will look like your printer and not a generic scanner icon.
I want to give you the best advice first by making sure you have adjusted the right print settings under Printing Properties for the printer: "Paper Mismatch Errors." This link outlines the most common place to make appropriate changes.
You also want to make sure you have adjusted the margins for those having this problem in Word 2010. "Change or Set Page Margins" so click this link for more information.
As far as Hallmark settings, I am not familiar with that software as it wasn't clearly defined which program you are using, but I do suggest as a general option with most print software, make sure you have selected a template that matches the paper you are printing on. If you could provide more information about which software or paper size or Avery number, I may possibly be able to help you or you can try to contact support for that software.
If none of the above selections help, you can always "Assign Alternate Print Drivers" to see if that allows you to print but the error you see is often related to the software you are using and not the printer. I hope this helps you. If not, please respond with the paper type, file format, and software you are using as I am always happy to help.