Lost some application icons

I recently installed the latest Windows Blinds and noticed that I'm getting generic icons for some data files that used to show thumbnaiul previews.  So far I've lost .dream and .flv file previews.  The .flv files are played through Real Player.  The .dream files have a nice but boring big D icon and the .flv files show the RealPlayer program icon.  What happened and how can I get the previews back?  I'm set to large icon preview in Vista Ultimate 64 bit.