[Jorney Huang]

http://www.youtube.com/watch?v=PZVywj4k8T8

I created a series of pngs by exporting a powerpoint file. I dragged the first png to Avidemux, and it import all pngs in that series. In 2.5.2(Right), all pngs are shown normally; conversely, in 2.5.4(Left), only the first png is displayed normally.