Actually the personality file is correct, however, the VDPL304LF is just quite an odd fixture. I mean, it is not anything like a scanner, yoke or other 'typical' effect. So VisualDMX gets a bit confused and thinks it is most likely a strobe, which it isn't either. But VisualDMX considering this fixture to be a strobe is just cosmetic, I would worry to much about it.
Nevertheless, VisualDMX should be able to control the light without any problem. Have you had a look at the 'Custom' tab, that is where i have put most of the fixture's controls. Is there anything specific that doesn't work?