[basco]

i had similar behaviour.
upgrading tvheadend (opdenkkamp's git) + xmltv in tvheadend + disable eit fixed it for me.
as far as i understand epg can be messed up because of faulty epg info sent by cable provider.
tvheadend i think is not as smart as a set top box in this respect by disregarding 'wrong' or 'no' epg...