My system is not going beyond 640x480x16 on Xvesa, although, it can work on 1024x768x24 on Xorg. I checked this using Puppy Linux.
I need to change to Xorg 7.4 and edit .xsession file accordingly. The document says that it should be modified to:
/usr/local/bin/Xorg -nolisten tcp &
but the present Xvesa line is:
Xvesa -br -mouse /dev/psaux,5 -screen 640x480x16 -shadow -nolisten tcp -I 2>&1 > /dev/null &
should I retain -I 2>&1 > /dev/null and write:
/usr/local/bin/Xorg -nolisten tcp -I 2>&1 > /dev/null &
kagashe