[ BUILD # : 200509261930 ]
[ JDK VERSION : 1.5.0_05 ]

1. Create a Module Suite
2. Create Module in it
3. Add a new "Window Component..." to the module.
4. module -> "Run Project" works just fine
5. suite -> "Run" works too, but
6. suite -> "Build Zip Distribution" produces the cryptic message: 
"D:\netbeans-5.0\harness\suite.xml:49: Must have set at least an application name ('app.name')"

without telling you anything about how to set the app.name.  A new user would be stopped cold. 

If you then
7. right click on the suite and click the "Use basic branding info..." box, you can indeed produce a zip file.

Please add an explanation to the error message, reword it, disable the "build zip" menu item, or do something else to "engineer out the error" or at least make it clear what you're supposed to do to fix it.   If you disable the "build zip" menu item, Help needs to tell you how to enable it.