I'm currently using Beta 19, and new toolbars (such as Colors, Piano, etc.) show 'Unknown Command' and not able to run them.
(http://tlds.dothome.co.kr/sesirine/error-1.jpg)
Clicking 'Unknown' buttons, there says:
"NWGetSpecialFolderPath 'C://Documents and Settings\user\My Documents' 1" and, "NWGetSpecialFolderPath 'C://Documents and Settings\user\Application Data' 1".
Based on your description, you must have customized your toolbars in the beta, and then again in the original NWC 2.0. This corrupts the toolbars.
The messages that you see are generated by our test command, which can also be triggered by
Alt+Z.