When you hit preview, the attachment goes away. Maybe that's part of the issue?
Yes, RenderAccel still might help, even with fvwm and xterm. It accelerates all sorts of things. Try it.
And when I said "disable the Ethernet", I didn't mean unload the drivers. I meant go into your BIOS and turn it off, so it's not even available when you boot. You may get an error when your network init script runs, but just ignore that.