I am on Windows 7 service pack 1 (64 bit).
Solidworks 2011 service pack 5 (I do not use 2012 until next year when all my customers may have updated by then)
When using the add on photoview, I go to select a material and during the process the dialog box will not show what the material is until it is applied and previewed on a part.
When I was on SW 2010 and Photoview was standalone the preview of materials worked then after about 6 months the preview pane was empty of previews.
The only changes this computer has ever seen is updates to SW and the standard window updates.
I have already contacted my Solidworks reseller for support and they do not see this as a problem.