Hmm, radio buttons save their current state with the patch when the patch is saved, even when "no init" is selected. To make matters worse, the button's display does not reflect that state when it first loads. That leads to weird things like this:
radio buttons save state with patch.pd
All I did was load the patch and click on the upper bang.

(Win 10, Pd 0.51.4 64 bit)

@jameslo Can confirm win7 Pd 0.50.
Looks like a bug introduced in Pd 0.46 or maybe later....... cannot tell.
Setting Pd to 0.45 compatibility fixes it..... but of course could well change other objects behaviours at the same time (see patch below).
wierd.pd
Seems to be work in progress......... https://github.com/pure-data/pure-data/issues/730
David.