I need to use Sikuli for automation but I am unable to take screenshots. The problem is that when I click on "Take Screenshot" or "Create Region" the IDE gets hidden but selecting area option does not appear....
Make sure you are using Java 6 not 7. If you try to run both on the same computer, make sure to take a look in the system32 folder. Because Java 7 copies java.exe and javaw.exe there. You have to delete/rename them.
Better Solution: Uninstall Java 7 and install Java 6. ;)