Strange problems in java

Dose any one know what can cause theses problems in a java program:

duplicate class: WorldEditer.dialogs.ObjectChangeInterface

cannot access worldediter.dialogs.ObjectChangeInterface bad class file:

The code was acting fine until I added a new class that used ObjectChangeInterface. For some reason the compiler allows me to use it in several other classes in the same package .

I noticed a spelling difference in the path and the package name: upper/lower case! That could explain it…

Obviously that .java-file is not a class file - wonder why javac gets confused here. Try to correct than package name and delete all .class file an probable dublicates of your java files. Then recompile.