I almost posted a question about this because my back was fucked up (not injured, but weakened and sore), but my upper body lifts were still improving. I had none of the classic symptoms of overtraining such as disrupted sleep - and I've been there before.
Well, it only took about another week before my bench and press stalled out as well. And this last comment has given me something to ponder. I had also seen the quote by Kroc and had thought, "Aha! that's what's happening to me as well".
Rip, have you had success with lifters over 40 doing TM? I've tried it three times, each time reducing the volume, and it only takes about two months before I spin out and start regressing. I am getting stronger, but this three steps forward, two steps back shit is getting old.
Regards,
Matt