Sounds like an issue when starting X on the installer. Unless there is some alternative installer options then you may be out of luck. In the past there as always been the safe bet of the TUI installer, but I'm not certain if this was ever made functional for VL6SOHO (I don't think it was). Other possibilities are booting using a specific parameter that will drop you at the shell prior to starting X which would give you a way of troubleshooting your problems with X and, although getting to the shell is simple enough, the task of configuring xorg from the shell is not trivial. I believe that the boot parameter to get you to the shell prior to X starting is either 'gui2' or 'gui 2' (no quotes, of course).