Here is what I did:
Opened PDN - OK
Opened file (a jpg) - OK
Image shows fine in PDN - OK
Then Layers>Duplicate Layer - OK
Duplicated layer selected and Effects>Blurs>Motion Blur - OK
Set at Angle 11.00, Distance 200 Pixels, unchecked Centered - OK
The image does not render either before or after pressing OK. I had waited several minutes before pressing OK.
The image in the Layers box is correctly rendered but not the main image.
Basically I followed Rick's Tutorial at rbrewster.members.winisp.net/t1/tutorial.htm.
AMD Athlon XP 3200+ @2.2gHz
1.5 GB RAM