Q: "Dude, my shaders are all fux0red and I'm getting nice white blocks everywhere. WTF ?"
A: Q3TA and Quake 1.27g are much more stringent on checking pakfiles now. More than likely what has happened is you have an older mod somewhere that is replacing some shaders in memory and you're getting all sorts of ugly looking graphics. My recommendation is to just bite the bullet and install Q3A to a *NEW* directory. I can almost guarantee that if you reinstall Q3A, Install either TA or 1.27g, then install the latest 1.27g compliant mods, most if not all of your graphics wierdness will go away.