XCode Debugger crash, but game runs on phone

I've been having this issue when I build and run my Unity project in XCode. The application installs but then the debugger comes to a screeching halt with a "EXC_BAD_ACCESS" error. But the application runs fine when I launch it on the phone. It's been irritating but now really need to actually use the debugger. Anybody have any idea? Unity 3.4 (it did this in 3.3). Happens with Debug and Release Mode.

There are some odd messages about serialization layouts and the UNITY_EDITOR #ifdef.

GDB Output:

A script behaviour has a different serialization layout when loading. (Read 64 bytes but expected 68 bytes) Did you #ifdef UNITY_EDITOR a section of your serialized properties in any of your scripts?

(Filename: /Applications/buildAgent/work/842f9557127e852/Runtime/Serialize/SerializedFile.cpp Line: 812)

Program received signal: “EXC_BAD_ACCESS”.