I got a error message in 2.6.1e version.
Assets/NGUI/Scripts/Editor/UIAtlasMaker.cs(116,42): error CS0117: `UnityEngine.SystemInfo' does not contain a definition for `maxTextureSize'
'SystemInfo.maxTextureSize' in UIAtlasMaker.cs was added from Unity 4.1
------------------------------------------------------------
#if UNITY_3_5
int maxSize = 4096;
#else
int maxSize = SystemInfo.maxTextureSize; // Error in Unity 4.0.x
#endif
------------------------------------------------------------