Upgrade 11-12 leaving old xorg alone
 

Does anyone know if it is possible to upgrade a 11-12 leaving the xorg 6.9 intact and not installing the new modular xorg with 12?

Sure, just don't upgrade anything from the /x and /kde directories from disc 2. Maybe /xap, too. If you need stuff from those check Linuxpackages for versions made for Slack 11.

not advisable. why do you want to do that?

I might be choosing to do the same or at least convert back to old xorg. After installation of Skack12 I have been having a lot of X issues. Mostly a lot of screen freezes that halt input.