I can confirm that this issue disappeared when I updated to 5.1.1 (Beta) using exactly the same source code / project. -- View this message in context: http://monotouch.2284126.n4.nabble.com/NSObject-Linker-Issue-introduced-with-5-0-4-tp4222474p4222621.html Sent from the MonoTouch mailing list archive at Nabble.com.