videos imported with iphoto not playing in front row.

i have imported .mov videos recorded using my nikon digi cam into iphoto. when i open that event in photos section in front row a blank screen appears.

when front row comes across a .mov video inside a photo album again a blank screen appears.

short and sweet, videos are not getting played.

these videos do play in quick time.

also, i have imported these videos in imovie too. however they do not appear inside movies section on front row.

any help?