I upgraded from vista ultimate to 7 ultimate and all of the pre-existing shows (DVRMS) display thumbnails in Recorded TV, but none of the shows that have been recorded in 7 (WTV) display the thumbnail of the show. When grouped by show instead of recorded date so that both types are mixed, the thumbnail is missing if the group has any wtv files in it. The groups that have only dvrms files display a thumbnail correctly.

Is anyone else experiencing this?

I experienced this with the Win7 beta - turns out that thumbnails were only being generated if the microsoft code was in use - it wouldn't generate thumbnails with the nvidia purevideo codec

I found this previous discussion regarding msmpeg2vdec.dll:

http://thegreenbutton.net/forums/p/77924/385073.aspx#385073

It didn't make sense to me to replace the dll, so I re-registered it via regsvr32 and now the missing thumbnails have all appeared.