TV-DVD connection

Hi,

I just bought a LG TV (37LH7000) and an LG home theater system (LG HT 462DZ).I connected the DVD to TV through an HDMI cable (TV-HDMI IN to DVD-HMDI OUT).TV is also connected to one digibox (cable antena) through scart cable.

If i'm playing a movie from USB (for example) the sounds goes through home theater speakears (like expected).But the problem is: if i'm pausing the movie and i'm switching the Tv to antena (to see the tv channels) and after that go back to movie and press play then the sounds is not coming through home theater speakers (the sounds goes to tv speakers).

My question is what is wrong?Is a tv or dvd problem?
Are my connections done wrong?

Thanks in advance for your answers