Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.
No catch in focus on my t-mount mirror on my K200D, either - it just fires away no matter what. Presumably the lens isn't shorting the contacts like it needs to, or the camera sense the lack of an aperture lever, or something. I suppose you might also try playing with the custom option having to do with focus indicators and screw mount lenses. Not worth it, as far as I am cconcerned - I find trap focus hopelessly ineffective (too many false hits until I turn the focus ring slower than I ever would normally need to, plus it only fires on perfectly center subjects, can't distinguish objects (like branches) in front of the subject from subject itself, etc.