The LX800 is printing over and over on the same spot. It is unwinding too much label stock inside the printer, causing the label stock to jam inside the printer.
1. Firmware. Make sure the printer has the latest firmware version installed. The latest version can be found here: http://www.primera.com/firmware_upgrade.html
2. Cover Closed. Make sure you are running the LX800 with the cover closed. Certain direct light can sometimes interfere with sensors inside the printer.
3. Driver Setting. Browse to the printer driver preferences by clicking on Start - Printers and Faxes - right-click on the Color Label Printer icon - select Printing Preferences. Set the Rewinder option to Yes. Now take all extra slack out of the roll of label stock leaving a single two inch loop hanging down. Try printing with the LX800 again.
4. Preprinted Stock. Preprinted stock or a black mark that shows through the front of the stock, can cause the printer to unwind all the stock inside the printer. See this article for suggestions.