Product Version = NetBeans IDE Dev (Build jdk8lambda-1727-on-20130516)
Operating System = Windows 7 version 6.1 running on amd64
Java; VM; Vendor = 1.7.0_21
Runtime = Java HotSpot(TM) 64-Bit Server VM 23.21-b01

I have the class:

public static class Duet
{
    int x, y;

    Duet() {}
    {
        this.x = 0;
        this.y = 0;
    }
}

I wanted to create getters and setters. 
In the dialog Generate Getters and Setters I have checked the class (and so both its fields) and the "Encapuslat Field" option.
NB modified the clas into the form:

public static class Duet
{
        private int x;
        int x;               //<- Here is the error
        private int y;

    Duet()
    {
        this.x = 0;
        this.y = 0;
    }

//Follows the correctly generated getters and setters
}