We have a 450 Turbo that has been having intermittent printing issues. It will be printing labels fine then suddenly, mid-print will stop. Pressing the feed button will reveal the ink had distorted and did not print correctly. Other times it will not stop mid-print, but still have the same distorted ink(vertical lines, faded/spotty ink for what is actually there. Just a big mess of ink, really.). I don't think it's a sizing issue with the template because the same exact label will print normally 3-5 times with no issue.
I've swapped it with a different 450 and the issue persists. Reinstalled the driver, tested a new USB cable, cleaned the printer with the Dymo LabelWriter Cleaning Card, used a brand new Dymo brand label roll, and restarted the unit. I've not found much luck on Dymo's site, didn't know if anyone else had seen this issue...