The official solution from roland includes a USB dongle to allow it to work with versaworks. same solution for non V pro 2's.
This is correct, however, when you flip that dip switch and then turn the printer on, it even shows SP-300V on the screen. I know people said the V's had upgraded pumps, etc but my father bought one new directly from Roland and his is using the same old style pump, etc that the SP-300 I recently bought used has and another SP-300 we have in another shop (which was bought new from roland) so it appears that the switch is the only difference?
I just checked at Roland's site and it seems they have updated firmware out (7.10), I'm running 6.90 so i'm going to update and try again. The firmware is for the SP-300,SP-300V,SP-300VS so I don't believe there is a firmware issue.
http://download.rolanddg.jp/en/color.html#sp3firm is the link for firmware download.