I have a set that runs with `X -dpms` to disable power management. `xfce4-power-manager` often crashes in memory allocation functions due to corruption. Running under `valgrind` revealed the culprit being `xfpm_dpms_refresh()`. What seems to happen is that `xfpm_dpms_init()` omits the xfconf creation if not DPMS capable. Later on `xfpm_dpms_refresh()` still gets called, and attempts to use the xfconf. Adding a simple check for `dpms_capable` in `xfpm_dpms_refresh()` fixed the issue. Potentially same issue as #30