In Yosemite Mail, setting Signature to None does not remove signature like in Mavericks Trying to understand if changed behavior in Yosemite is expected or a bug.

In Mail.app in Mavericks, when I compose a new email, my signature would default to being there. If I then set Signature to None, Mail would automatically remove it from the mail body. 

In Yosemite, setting Signature to None does not remove the signature. In fact, if I set Signature to None then back to my signature and repeat, it keeps inserting new copies of my signature.

It seems like Yosemite doesn't keep track of where it inserted my signature the way that Mavericks did. Does anyone know how to get the previous behavior?
It seems that this has finally been fixed in El Capitan (I'm currently using Mail 9.2 on OSX 10.11.2).