Random programs popping up on blank channels

hi i own a eur0v0x max v 2008 and when i did a scan i got all the channels i wanted plus a few blank ones usaully named tvch12(or something like that anyway) so i shoved all the blank one at the end of my channel list, o bviously some of them are just channels that need to be renamed but most are blank(well most of the time)

anyway as i was flicking through the stations i have noticed random programes off differant channels just popping up on some of them that usaully stay on for a bit but then freeze and service unknown message comes up.

anybody know what this is? i reckon its probably peoples recordings from v+ boxes in the area but i'm just guessing