Yeah i had the same, it just seems to always be films on my bsepg channels True Entertainment, Men Movies etc
Read that you should 'enable the options in Big Screen EPG for both injecting and 'fixing' the Movie related metadata'
Read that here [SOLVED] How to get Movie Metadata Inserted? - Australian Media Center Community

But i checked and i have those options turned on and still no cover art shows up, i just like to browse whats coming up filmwise and often the cover art is useful