let's set aside some time to remote in, so I can see what's going on. I no longer use MythTV in LinuxMCE, so would need to look at an actual installation, to see what's going on.
We have a number of scripts in MythTV_Plugin which handle guide refresh, but I am not sure where they are being called anymore, greps aren't being forthcoming:
/usr/pluto/bin/MythTvDailyFillDB.sh
/usr/pluto/bin/MythTvInitialFillDB.sh
-Thom