Blender not working right.

Anybody know how to fix this? I’m on a Dual G5 2.5 1GB ram with a Nvidia GeForce 6800. Os 10.3.6 As you can see the highlights aren’t showing right, I can kinda count down to where I need to be but it doesn’t always work.

on my g5 abut also on the pc bths version of blender is somehow buggy,
from not been able to select thing to crashed to not accepting keybord commands.