X is totally horked

Delete your /etc/X11/xorg.conf. Seriously. (Well maybe move it to xorg.conf.not just in case). Modern xorg will auto-detect just about everything and probably start up just fine on its own. If this works, you can pull the default config out of /var/log/Xorg.0.log, put that back into /etc/X11/xorg.conf, and add any customizations you need. Of course, if you don't need to customize anything, you don't even need to do that.

Compiz Won't Start on Older Radeons with dual-head

Older radeons had a 2048x2048 max texture size limit. Compiz draws the background as a single texture, and if the total screen size is bigger than the max texture size, it will give up. If you disable the check for this though and tell compiz to start anyway, it works mostly arlright; it just can't draw things that span across both screens. You can disable the check by editing the /usr/bin/compiz script and having the function that checks max texture size return 0 in both cases. To get rid of the garbage that hangs around on the right side of the screen, you can stick some window there using devilspie. See the attachment for an example solution.

Maximized Windows turn Black!

Possibly related to a bug in the proprietary NVidia driver. This problem occurs when you run out of Video RAM. To alleviate this, tell compiz to use indirect rendering. You can restart compiz with `compiz --replace --indirect-rendering'. If that works, you can make it permanent by editing /usr/bin/compiz and adding --indirect-rendering to the COMPIZ_OPTIONS=... line.

Maximized Windows Span both Monitors

Compiz is failing at auto-detecting output screens/monitors. Open `ccsm'. Go to General->General Options->Display Settings. Uncheck "Detect Outputs". Set the outputs to what they really are, ie 1600x1200+0+0 and 1600x1200+1600+0.