Radio Commands in ToolBar - eclipse-rcp

Question

I'm building a plugin that display images with some exclusive style.
Think something like you've got an colour image, and you can choose style "Black and white" or "Sepia" etc..
My plugin is like this:
<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.4"?>
<plugin>
<extension
point="org.eclipse.ui.commands">
<command
categoryId="fr.comp.app.category"
defaultHandler="fr.comp.common.styles.impl.DefaultStyle"
id="fr.comp.common.styles.defaultStyle"
name="Default Style">
<state
class="org.eclipse.ui.handlers.RadioState"
id="org.eclipse.ui.commands.radioState">
</state>
</command>
<command
categoryId="fr.comp.app.category"
defaultHandler="fr.comp.common.styles.impl.SepiaStyle"
id="fr.comp.common.styles.SepiaStyle"
name="Print Style">
<state
class="org.eclipse.ui.handlers.RadioState"
id="org.eclipse.ui.commands.radioState">
</state>
</command>
</extension>
<extension
point="org.eclipse.ui.bindings">
<key
commandId="fr.comp.common.styles.defaultStyle"
contextId="org.eclipse.ui.contexts.window"
schemeId="fr.comp.app.scheme"
sequence="F1">
</key>
<key
commandId="fr.comp.common.styles.SepiaStyle"
contextId="org.eclipse.ui.contexts.window"
schemeId="fr.comp.app.scheme"
sequence="F6">
</key>
</extension>
<extension
point="org.eclipse.ui.menus">
<menuContribution
allPopups="false"
locationURI="toolbar:org.eclipse.ui.main.toolbar">
<toolbar
id="fr.comp.app.style.toolbar">
<command
commandId="fr.comp.common.styles.defaultStyle"
icon="resources/default.png"
style="radio">
</command>
<command
commandId="fr.comp.common.styles.SepiaStyle"
icon="resources/sepia.png"
style="radio">
</command>
</toolbar>
</menuContribution>
</extension>
</plugin>
My Handlers execute look like this:
public Object execute(ExecutionEvent event) throws ExecutionException {
// blabla change the style
final IStyleManager styleManager = MagicHub.getService(IStyleManager.class);
// ... end blabla
// change the state of the org.eclipse.ui.commands.radioState of the cmd
Command command = event.getCommand();
State state = command.getState(RadioState.STATE_ID);
state.setValue(Boolean.TRUE);
return null;
}
Ok, now I've got a nice toolbar, that display my commands.
I can click them, and the style apply.
I can use my keybinding too, and the style apply too.
But, when I use keybinding, radios button is not toggle properly.
What am I doing wrong ?
BTW: my target platform is Kepler.