Able to Copy Text from Uneditable Text Boxes(JTextfields)

Hi please any one can help me on this,

I have JTextfields in my application, i have overrided the JTextfield copy method using

public void copy();
Jtextfield.setHighlighter(null);

So i am not able to copy text from JTextfield to other text editor in windows.

In Linux/Solaris MouseDrag on Jtextfield data and paste in text editor also not able to paste data
but MouseDrag on Jtextfield data and using center button of mouse(scroller) able to paste data on other text editor
same thing is happening with double click and tab also.

In windows it's working fine.