I recently noticed that the hinge clamp (on the downtube) of my Ritchey Breakaway road bike has rotated during a ride. I'm talking about 30 to 45 degrees. It's happened the last couple rides I've done. I have never had this issue before and I did not notice any difference in the ride feel (i.e. no excess flex, etc. in the frame). As instructed by Ritchey, I have not lubed the screw. I tighten it to 4nm with a torque key (Ritchey brand). Everything seems good. The screw does not appear to be any more loose (it's still torqued at 4nm), so I'm wondering if the clamp is stretched or something.
My main concern is the part failing. I don't want to find out what happens if it does! It is also a problem if it rotates enough it starts to interfere with the shift cables.
Any suggestions as to what is causing this or has anyone had this happen to them? I will replace it with a new one to see if it continues to happen, but this one only has about 1,000 riding miles on it and hopefully this will not be a continuing issue.

Another question: Ritchey does not recommend lubing the threads of the clamp screw with grease. Do any of you guys use a light threadlocker (such as Loctite 222 (purple))? Just leave it dry? What say you?
Thanks!