PSP5 cannot see files on startup

[StephenG]

I've been using PSP5 for some time and suddenly when I start up the application it just shows blank spaces where images should be. It can see the pictures file folders but does not show images. I un-installed the application and re-installed it. It worked about twice but has started doing the same thing again. It seems to recover if I do a complete re-start each time I use it. But this is hardly convenient. I'm using Win 8 in 64 bit mode.

[trueblue]

Have you installed all the updates/patches?

[StephenG]

"Have you installed all the updates/patches?"

Thanks for your reply, I hope you can advise.

All available updates and patches have been installed.
The application seems not to be able, intermittently, to read image files.
If I click on an image in a folder, PSP5 opens and displays a message saying that the image type is not recognised. This is with jpg's!
If I start PSP5 in Manage mode all I get is a row of blank rectangles with a dotted circle (not rotating).
I have ensured that the file types are selected in the box where image file types are listed.
I have made PSP5 a default application for image files.
PSP5 will function if it is loaded straight after turning the PC on or after a re-boot. But do so much as look at email, use the web browser or anything really and I get nothing.
The puzzle is that I have been using the application for some time and it has only recently started doing this.
Sure beats me.