Disable unity ui input is not working

[Thaina]

It cause error with PowerUI.Input.UnityUICaster at

powerui/Source/Default Managers/HtmlUIPanel.cs

Lines 95 to 100 in 364576e

	// Include the Unity UI when handling input:
	if(PowerUI.Input.UnityUICaster==null){
	// Get the caster:
	PowerUI.Input.UnityUICaster=img.canvas.GetComponent<UnityEngine.UI.GraphicRaycaster>();