Calling commitEditing text field loses focus

I have a text field whose value is bound through an NSObjectController. =
Before performing certain actions I call -commitEditing on that object =
controller to make sure I have the current value from the text field. =
What I notice is that if there are any uncommitted changes to the text, =
the text field loses focus due to this call. This is certainly not what =
I want, I just want to commit the edit. I also don't recall this to =
happen in the past, but I am not sure for how long this has been going =
on. Also, the focus is not lost when the text had not changed since the =
last commit. To me this sounds like a bug. Can anyone confirm this is a =
bug, or tell me why this would make sense? Or tell me whether there is =
some kind of setting to change this behavior?

thanks,
Christiaan