I am running OS 10.4.9 on a G-4 PowerBook using a Dymo LabelWriter 400. My installation went fine and it immediately worked with my Apple Address Book.

I had the previous version off Dymo on my computer in the Application Flolder. First I removed it and placed it on the Desktop. Next I disconnect my USB from LabelWriter to computer. Then did an installation and after that was complete reconnected the USB to Labelwriter. It worked without a restart. I then trashed my old Dymo folder on the desktop which i kept just in case. Did a Permissions Repair. All works well. By the way I used the installation icon in the English folder. The one standing by itself would not work properly.

I have a Dual Dymo at home running on a G-5. Will try that to night. I also have Dymo Stamps running on one side of this Dymo so am wondering if I should do this upgrade?