Hi guys.  I use Astro file manager and have transferred some Pdfs to my Nexus 7.  However, the files just show in the folders as the standard Pdf icon, not the usual preview image of the document, which is making it a bugger to identify which is which.  When I have opened one with Adobe Reader and then later on opened up Adobe Reader and look at the list of recently opened documents, it does then show some, but not all preview images.  Meanwhile in the Astro folder they still have the standard Pdf icon.

Any ideas on how I can get the Pdfs showing their preview icons in Astro File Manager?