I'm in the process of migrating a project from NGUI 3.0.8f2 to 3.6.8, and so far I've only come across one issue.
Setting a widget's Notify to call a method which has overloads, i.e. foo(), foo(int a), will throw an error. In the quoted example below, there are two SetFXVolume methods, one taking an int.
Could not find method 'SetFXVolume' on SetCurrentValue
UnityEngine.Debug:LogError(Object, Object)
EventDelegate:Cache() (at Assets/NGUI/Scripts/Internal/EventDelegate.cs:388)
EventDelegate:get_isValid() (at Assets/NGUI/Scripts/Internal/EventDelegate.cs:193)
EventDelegate:IsValid(List`1) (at Assets/NGUI/Scripts/Internal/EventDelegate.cs:629)
UIProgressBar:set_value(Single) (at Assets/NGUI/Scripts/Interaction/UIProgressBar.cs:135)
SetCurrentValue:SetFXVolume(Int32) (at Assets//Code/SetCurrentValue.cs:848)
SetCurrentValue:Start() (at Assets//Code/SetCurrentValue.cs:128)
This hasn't been a problem with prior versions of NGUI and I can't see any mention of it in the release notes?