I'm running JSBuilder2 command line on Windows Vista and Getting the following error..

It actually builds the '-debug.js' version of the file and then fails to create the minified version. Any ideas?

Code:
Loading the 'Test Project' Project
Loaded 1 Packages
Building the 'motoui - all' package as 'compiled/test.all-debug.js'
- There are 12 file include(s).
- - ../app/overrides/overrides-bugfixes.js
- - ../app/overrides/overrides-enhancements.js
- - ../app/overrides/vtypes.js
- - ../app/forms/config.forms.js
- - ../app/forms/config.forms.Test.js
- - ../app/forms/config.forms.Import.js
- - ../app/layout/config.print.js
- - ../app/layout/config.NavPanel.js
- - ../app/layout/config.TaskUIPanel.js
- - ../app/layout/config.AppHeaderPanel.js
- - ../app/layout/KRI.languages.English.js
- - ../app/layout/applayout.js
Exception in thread "main" java.lang.NullPointerException
        at com.extjs.FileHelper.listFiles(FileHelper.java:103)
        at com.extjs.JSBuilder2.writeHeadersToTargets(JSBuilder2.java:276)
        at com.extjs.JSBuilder2.main(JSBuilder2.java:44)