BlackBerry Plug-in 1.3 Beta is not compatible with ADT (Android Development Tools) version 21. I also experienced this bug on both Windows 7 and Mac OS 10.7.5.
After an hour I finally found a solution (workaround):
- Uninstall ADT and BlackBerry plug-in from Eclipse
- Manually download ADT 20 from here
- Install ADT as Eclipse plug-in from the downloaded archive
- Install BlackBerry plug-in 1.3 Beta
Please note that I have also posted the solution with more details at my personal site