I use proguard (support in mtj plugin) to obfuscate a project that has some third party jars but it gives me errors:
Your input classes appear to be inconsistent.
You may need to recompile them and try again.
Alternatively, you may have to specify the options
'-dontskipnonpubliclibraryclasses' and/or
'-dontskipnonpubliclibraryclassmembers'.
It seems that proguard look for the classes in JavaSE not JavaME. It only happens with projects that use third party jars.
One thing that I saw is when I used third party API provided by OEMs like LG etc, I needed to set the proguard obfuscation level to 8 when compared to 9 which is the maximum level. Hope this wells.