[Xrystal]

It calls this function in ButtonBar.lua whenever the slash command is executed:

function nUI_ButtonBars:setUserBarOptions( bar )

	for i=1,#bar.Buttons do
		for j=1,#bar.Buttons[i] do
		
			local overlay = nUI_ButtonMap[bar.Buttons[i][j]];
	
			overlay.layers.count:SetAlpha( nUI_Options.barStackCounts and 1 or 0 );
			overlay.layers.name:SetAlpha( nUI_Options.barMacroNames and 1 or 0 );
			overlay.layers.hotkey:SetAlpha( nUI_Options.barKeyBindings and 1 or 0 );

			if not nUI_Options.barCooldowns or not nUI_Options.barDurations then
				overlay.layers.cdc.value = nil;
				overlay.layers.cdc:SetText( "" );
			end								
		end
	end
end

So it looks like it only turns it off automatically. As to the settings in Button.lua it looks like it validates value with text and updates if it is different and flagged for display.

Changing the relative section in the function above to the following solves the problem but I am not sure how it will affect the rest of the overlay system.

			if not nUI_Options.barCooldowns or not nUI_Options.barDurations then
				overlay.layers.cdc:Hide();
			else
				overlay.layers.cdc:Show();
			end

In fact it could be changed to set the alpha value like the other options are dealth with. That seems to work fine too.

But, it doesn't seem to solve the following problem :

Arcane Torrent has a brief duration timer which is stuck at 0.0 until the cooldown timer updates again. Here's a picture to show you: