I just downloaded NGUI 2.3.6a unto a new Unity 4 project and now have 7 hard script errors:
Assets/NGUI/Scripts/Interaction/UICenterOnChild.cs(11,28): error CS0426: The nested type `OnFinished' does not exist in the type `SpringPanel'
Assets/NGUI/Scripts/Tweening/TweenAlpha.cs(55,33): error CS0115: `TweenAlpha.OnUpdate(float, bool)' is marked as an override but no suitable method found to override
Assets/NGUI/Scripts/Tweening/TweenFOV.cs(24,33): error CS0115: `TweenFOV.OnUpdate(float, bool)' is marked as an override but no suitable method found to override
Assets/NGUI/Scripts/UI/UIFilledSprite.cs(189,30): error CS0115: `UIFilledSprite.OnFill(BetterList<UnityEngine.Vector3>, BetterList<UnityEngine.Vector2>, BetterList<UnityEngine.Color>)' is marked as an override but no suitable method found to override
Assets/NGUI/Scripts/UI/UISlicedSprite.cs(116,30): error CS0115: `UISlicedSprite.OnFill(BetterList<UnityEngine.Vector3>, BetterList<UnityEngine.Vector2>, BetterList<UnityEngine.Color>)' is marked as an override but no suitable method found to override
Assets/NGUI/Scripts/UI/UITexture.cs(48,30): error CS0115: `UITexture.OnFill(BetterList<UnityEngine.Vector3>, BetterList<UnityEngine.Vector2>, BetterList<UnityEngine.Color>)' is marked as an override but no suitable method found to override
Assets/NGUI/Scripts/UI/UITiledSprite.cs(47,30): error CS0115: `UITiledSprite.OnFill(BetterList<UnityEngine.Vector3>, BetterList<UnityEngine.Vector2>, BetterList<UnityEngine.Color>)' is marked as an override but no suitable method found to override