SW2010 - XP-Pro - Windows Explorer Thumbnails too small to see

Solidworks 2010 seems to be a bi-polar on thumbnail graphics that it generates for Windows Explorer.  If I view a folder or search result as thumbnails, 90% look like a dot in a blue field. Oddly enough, some look like perfectly proportional thumbnails, as you'd expect them to be. Opening and re-saving one of these mini-thumbnails doesn't appear to solve the problem...  Does anyone know how to turn this back into a useful feature?

SolidworksUser Interface