The problem is that when I have completed deinterlacing with Fieldskit and start using Twixtor I am unable to preview my work -- preview remains on the first frame when playing. I am working in HDV, so have been using proxy files. But despite these fairly small files, I haven't had any luck. Obviously with time manipulation, you want to see specifics of your work, ideally in real time.
Note, HDV is a special animal depending on the camera that generates it. In some camera progressive frames are stored on two fields, and instead of deinterlacing you can just use the Reinterlace plugin in FieldsKit with mode "Combine Fields" (eg it sometimes is tagged as interlaced but is not except the two fields that forms the real progressive image can be spread across 2 frames -- eg frame 7 is spread across frame7 second field and frame8 first field...)