XFree_Mach64-3.3.6-20 powers off my DPMS monitor on exit and I cannot recover the console no matter what I do. The machine is alive and well and can be telnetted to from another machine. If I type startx again from the command line (blindly of course) the X desktop appears again and the monitor wakes up. lspci shows that card is ATI 3D Rage LT Pro AGP-133. Earlier versions of the Mach64 server work with no problems.
power saving can be notoriously flakey. We recommend that you disable power saving if you are experiencing problems.