Why when playing music from APTV3 stored in cloud does it stop after 5 or so songs??

I have loaded all my itunes library to the cloud, (itunes match) £21.99 per annum, i switch on Apple tv3 which is hard wired to my virgin superhub 20mb, i choose music (itunes match) and select a tune or playlist or an album, hit play and we have music, APTV3 has HDMI into AV amp so amp plays music to speakers, but after say 5 or so songs it stops playing, as though its paused. But the marker just sits at the start of the song and the little loading sign just spins!! frustrating!!!!

Any ideas anyone please

just to say if i play from laptop or iphone and airplay it to APtv3 its fine!!! No drop outs, stutter or stops!!

darrell