ToggleButton actionPerformed called om mouse rollover in GTK Look And Feel

ToggleButton on GTK look and Feel is triggering action events on mouse rollover on the component.

the attached application is a demo forlooking at the features of JProgressBar The Buttons in the "UI Features" Panel are JToggleButtons which are used to toggle features of the ProgressBar.

Using the Look and Feel Combo the Look and Feel of the application can be changed to the any of the available look and Feels.

On First running the application the application shows in the Metal L&F.
Clicking on the toggle buttons should produce the appropriate actions.

Change L&F to GTK+
move mouse over any of the toggle buttons and mouse over of the buttons causes the actions associated with the toggle buttons to happen.

Now even if the L&F is switched back Metal or Motif the same problem persists.

I did the development on ubuntu linux and saw this error in the command prompt
<snip>
(<unknown>:7168): Gdk-WARNING **: locale not supported by Xlib

(<unknown>:7168): Gdk-WARNING **: cannot set locale modifiers
</snip>

I did not get any errors running on Solaris Sparc 10