This version improves detection of supported browsers, or more precise unsupported ones. There is a known problem with Safari 5.1 running in 32-bit mode on both Mac OS X 10.6 and 10.7. Before version 1.2.3 the library did not detect this problem. Now, the call to dymo.label.framework.checkEnvironment() will return an error.
The js script file is available from http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.1.2.3.js.
The http://labelwriter.com/software/dls/sdk/js/DYMO.Label.Framework.latest.js has been updated to version 1.2.3 as well.