OS: Ubuntu 12.04 64-bit
Printer: Dymo Labelwriter 400
Task: Print 99019 postage label from my ebay
Result: Print job goes into queue but does not print; job hangs.

Observation: Labelwriter prints test page; job hanging is peculiar to Firefox
Observation: Using Chrome browser job sent to printer does print, not correctly formatted, but that's another issue.

I have configured my settings in Paypal for the Labelwriter 330 Turbo and installed Sun Java per Paypal instructions. The Labelwriter appears to be installed correctly because I can print labels to PDF then print from PDF to the Labelwriter, with the formatting issue.

I'm looking for suggestions to help me figure out why labels will not print from Firefox yet will print from Chrome.

Even more importantly, I'd like to figure out how to get the labels to print properly formatted for the 400 whether I have to print to PDF then to the Labelwriter or use Chrome. Hopefully, this can be resolved before I run out of labels.

Meanwhile, I'll go back to printing half sheet labels until I can figure this out. gLabels appears to work with the printer too.

Ideas on where to start?