Problem trying to cut from a specific time

Hey all,

I am trying to cut a specific section from a home movie but I'm having problems. I know the start and end time I want but when I set Handbrake to use those times the result is not what I asked for, but starts slightly ahead. If I try one or two seconds earlier it is the exact same, but if It try several second earlier it jumps several seconds backwards. I cannot get it to start at the point I want (in between the two it gives me). I have tried Format Factory with the same result.

Would this be a problem with the specific video file, or is it a common problem? Is there a workaround?