Well, the only thing you can do is set HB to use a 24 fps constant frame rate. Of course it will drop one frame every second on a 25 fps source.
strange, info in vlc reports 24fps, and the audio appears in sync, but the pitch hasn't changed. how does that work??
What exactly do you mean by "pitch" ? I will presume you mean the pitch of the audio track. HB will keep the video and audio in sync even when you change the frame rate. It will not change however the pitch of the audio. Video is synced to audio basically.