http://www.pentaxforums.com/news/k-3-mirror-flop-fix-from-ricoh.html
"Thank you for contacting RICOH.
We have been informed that there is now a shop adjustment that
can be made to help resolve/reduce the reported K-3 "mirror-flop" issue.
I recommend you return your camera directly to RICOH Imaging Company at
the address listed below for examination."