I had the same problem, the movie just frozzen, showing just a blank picture.

I finally fixed my problem by doing the following
1 Go to Start ==> Run ==> and type in "cmd"
2 First, type in: regsvr32 -u C:\windows\system32\l3codecx.ax
3 Then type in: regsvr32 C:\windows\system32\l3codecx.ax

hope this helps you too