You can also change the text size. I have VL 5.9 Light running at 640x480 and it looks fine after a little tweaking. I really, seriously suggest you go that route.
VL 5.1 is three years old and completely unsupported. I guarantee it to have security vulnerabilities that will never, ever be patched.
Re: the ChangeLog, there were undoubtedly development builds that were never released to the public. I still have a CD with Vector Linux SOHO 5.8.6 RC2 somewhere. The final version never happened.