[FFmpeg-user] image extractions using image2 don't line up with video

[Marc Reichman]

I am extracting images from videos to use as a thumbnail storyboard such 
that clicking images will advance a video player to the time of the 
extracted image.

I'm using the following command line:
ffmpeg -i input.m4v -f image2 -r 1/1 -s 96x72 image%06d.jpg

I am finding that the extracted images do not line up with the video 
used to extract them. This for example, should be outputting one image 
per second of video, but the images seem to lag behind the video time 
about 1-2 seconds. Am I doing something wrong with the command line or 
can I add something to help it line up better?

Thanks,
Marc