[mikerigel]

It has the same behavior than gregkr's body, the mirror freaking out after some shots, and also the physical shutter button is sometimes getting stuck in the down position.. I know it's not a "pro" camera so I guess it didn't appreciate the 40000+ photos I took the last 3 months for work!

It also started acting weird like it won't accept my Sigma lens anymore... the aperture value is messed up with it, like will go down to F/1.2 even though the lens opens at F/4 maximum, and no auto-focus with it.

Anyway, it's going to get serviced and hopefully it will all be good.
One difference between my K-r and Gregkr's: I didn't drop mine, but both our K-r had the same mirror problems... hopefully it's just a coincidence and not a manufacturer default.

[hcarvalhoalves]

Have you tried fresh batteries? Maybe that's playing havoc with the electronics. I would think about this considering your shutter / lens aperture problems, it doesn't seem to be mechanic failure.

[mikerigel]

Yes, my battery is getting recharged every 2 days, and it happens anyway.
And even if that was just a battery matter, the autofocus problem would happen with all my lenses, not just the Sigma.

[gregkr]

sorry to hear this Mike. (but I feel less alone)
I have to precise that my Kr was only used with Pentax lenses (da 21mm + 35mm 2.4) and the the drop didn't change anything to the pre-existing mirror issue. Haven't had any focus issues (except FF of course)
Bring it asap to you dealer, don't repeat my mistake ;-/