I was playing with MTJ and i found a issue with the preverification settings. if the user selects on JavaME preference "Use specific configuration" (such as CLDC 1.0). This will cause the build process to fail with an error message like:
Errors occurred during the build.
Errors running builder 'Preverification Builder' on project 'teste'.
For input string: "CLDC"
The workaround for that is just to return the preference to "Use JAD File Setting". This will fix the problem and the build will work properly.
The issue is on the mechanism that save the "CLDC-1.0" or "CLDC-1.1". There is a bug there and the preference is actually saving only the String "CLDC". This cause a NumberFormatException.
There was a discussion a while ago about that on the list:http://dev.eclipse.org/mhonarc/lists/dsdp-mtj-dev/msg01322.html