Created attachment 141859 [details]
Both classes

1. Create 2 simple java classes ClassA and ClassB

package test;

public class ClassA {
	public void test() {
        System.out.println("m1");
    }
}

----------------------

package test;

public class ClassB {
	public void m() {       
        ClassA a = new ClassA();
        a.test();
    }
}

2. Open both classes in editor like showing on attached image

3. Put caret into "a.t|est();" in ClassB where '|' is position of caret

4. Using Ctrl+R invoke Rename dialog, type new name "ttt" and press Refactor

5. Leave ClassB.java tab in editor selected, presa Undo and confirm, press Redo and confirm

6. Celect ClassA.java tab in editor, press Undo and confirm

>> Now method in ClassA has name "test" but in Classb it is named "ttt", so code is not compilable

Product Version: NetBeans IDE Dev (Build 201310290001)
Java: 1.7.0_45; Java HotSpot(TM) 64-Bit Server VM 24.45-b08
Runtime: Java(TM) SE Runtime Environment 1.7.0_45-b18
System: Windows 7 version 6.1 running on amd64; Cp1252; en_US (nb)