I experienced a problem early on with my 330 that required me to upgrade the flash rom of the machine. To do this, I needed a $15 cable from DYMO that connected the labelprinter to a serial port on a PC (no mac support!). I downloaded software for my specific machine from their ftp site (
ftp://ftp.dymo.com) Go to the folder named Printer Updates, find the folder for your printer, and download the appropriate PC files needed to upgrade the ROM. This corrected the problem when I did it two years ago.
Remarkably, the upgrade to the DYMO software version 7.7.7.1, which I installed because it said it was compatible with Leopard, appears to have "reset" the ROM on my printer (I verified this). As a result, I needed to repeat the process detailed above.
Unfortunately, what I did not realize during this whole process is that my trusty 330 actually is NOT compatible with their DYMO postage system. Apparently only three models (the Twin, the Duo, and the 400 Turbo) are compatible with the online postage system. Dymo did offer to upgrade the ROM for free, as long as I paid for shipping back and forth (even though their web site claims a $75 fee for doing this.) In addition, they offered my a $30 discount on the Twin ($159 vs. $189), which was not much better than buying online somewhere.
So if you are continuing to experience problems with the 330, consider the upgrading the ROM firmware in the printer. You'll need a PC with a serial port, the $15 cable from DYMO (it looks like a phone jack to serial port connector), and about 30 minutes to download the software, run the upgrade program, etc. For me, I've decided to upgrade to the Twin, though I wish I had had a more positive experience with their customer service department regarding the measly $30 discount.
Cheers,
Chris Moggia