To allow Anthem to be 100% functional under mono, you have to add a single line in Manager.cs, in the AddCallBacks method concerning ASP.CheckBoxList (line number 1354):
...
ASP.CheckBox controlToRepeat = (ASP.CheckBox)((ASP.CheckBoxList)child).Controls[0];
controlToRepeat.AutoPostBack = false;
//MONO FIX
((ASP.CheckBoxList)child).AutoPostBack=false;
...
This is because the way mono set autopostback for CheckBoxList is not the same than native ASP.net
When done, works perfectly under Mono 2.4.2