Restart Ripping halfway thru film

[KinKade]

I'm using SmartRipper.The film section of the DVD stopped ripping after about 85%.There are 5 VOBS in this section.How do I restart on the last VOB of the film without recording the first four again which I aready have?I've tried ticking off the relevant boxes but it just says VOB1 alaready exists do you want to overwrite?!There must be a way to avoid this!