I have had this sort of thing with my adaptall lenses and adapters. Often it is fixed by giving the lens a "wiggle", or switching on and off.
Test that the lens + adapter is operating correctly in any case by taking some test shots.
As far as focus confirm goes, for that check you camera settings. That should not be affected by or dependent on whether the PKA is playing up or not (which you can confirm by taking it out of auto aperture mode and using Manual).
There are some more useful links on my page:
Information page on Tamron adaptall, adaptall-2 system and lenses
UPDATE: and I'd forgotten about this:
https://www.pentaxforums.com/forums/114-maintenance-repair-articles/50689-fix...a-adapter.html
I was just fiddling with two PKA's acquired with lenses that weren't registering. 10 secs scratching with a small screwdriver - fixed!
Last edited by marcusBMG; 03-02-2015 at 09:06 AM.