Hi,
I also have k200d and FA 50 1.4 - no problems, so far.
Try to go to pentax tech support: Pentax Imaging - Home, they have chat feature. You can try to reset the camera (Chapter 11 in the manual).
Good luck,
__________________
AK
~~~~~~~~~~~~~~
K200D, DA*16-50, DA*50-135, FA 50 F1.4, DA 70 F2.4
|