I flashed my K530i sucessfully to W660i. No problems, as they are the same phones in different covers. There are no bugs!
The V630 is the Vodafone version of the K610i. They have nothing to do with K530i/W660i.
The V640 is the Vodafone version of the K630i. They have nothing to do with the K530i/W660i, as these have HSDPA.
Everyone, who bothers to actually read the spec sheets and check the hardware pics for layout details, can find this out him/herself and avoid useless flash experiments.