I recall suggesting that you swap out that mallory with your stocker to see if it made any diff... You did read that didn't you? You had my brain going wondering what it might be (if I were in your shoes). As I also stated earlier I have had many problems with TFI modules going bad, so I can relate to your problem totally.
I am glad to see that you have finally located your problem. I'll bet you feel a little bit better...
Later