If you configure XMLTV to delete old programs before importing tvguide.xml and you are using PowerScheduler, sometimes XMLTV will allow the system to go to sleep after having deleted existing programs but before importing the new tvguide. When this happens the system will not wake up for recordings because EPG will be empty before the sleep. The system will wake up again for the next EPG grab.

h4. Additional Information
XMLTV will not allow the system to sleep while importing but there is a small margin between issuing the SQL to delete old programs and the start of the import. If PowerScheduler attempts to put the system to sleep during this time, it will succeed, and the import will not be completed before the next wake up which will be on the next scheduled EPG Grab.

See: http://forum.team-mediaportal.com/xmltv-137/stay-awake-whilst-loading-epg-73426/