First have you updated PDCU to version 4.21? The version 4.21 is more stable although not perfect than version 4.11.
Second I advise to transfer first your files to your computer with the card or the cable. Then open PDCU to look at the files in your computer.
If you have a lot of photos in the same directory, PDCU may run out of memory. I would suggest that you put a limited number of shots in a given directory (eg 100 shots) and open the files in that directory with PDCU.
Note that PDCU will only PP Pentax proprietary photos. Make sure that you do not modify any original shots before opening PDCU.
Hope that the comments will assist...