Do you use the Screensaver password option at all? If so, because you don't log in when the machine wakes due to the schedule, the system assumes it is an accidental wake event and will subsequently go back to sleep again after about 30s or a minute. This is a problem I came across when I first started using my EyeTV software. To work around it, to maintain my system security I have to manually fast user switch to a second user running a Simple User account that is as locked down as is possible, and leave the password option for the screensaver off.