My LG HT805TQ home theater system won't Playback DTS sound!!!

I recently bought their LGHT805TQ home theater system (like 3weeks ago), i never even bothered to check the logos on the pack cos the older model of their home theater that i have plays DTS sound flawlessly, so automatically i assumed this would do the same and with a better experience, it never even occurred to me for a sec that i should test its DTS capability cos i've never had any experience of dvd players not being able to play DTS audio from dvd movie. When i got home, i set the whole thing up and popped in my TERMINATOR 2 ULTIMATE EDITION DVD and i selected DTS audio from the dvd menu and i played the movie, to the utmost shock & dismay there was no sound!!! i stopped it, checkd the wire connections, replayed etc. but still no sound, then i switched to dolby 5.1 and the sound came out, i tested again with DTS on Terminator 3 DVD still no sound!
Ive read & learnt that people say that DTS is old technology but seriously i prefer to watch my movie with DTS audio cos its stronger and comes out more powerfully than Dolby Digital. Right now even repacking the whole thing and sending it back to the retailer is quite a trouble for me considering i bought from like about a 60miles from where i live & i'll have to haul it back there myself and that whole package is as big as a car!
I hope anyone help me out with this issue of the DTS?? i'll appreciate.. otherwise i'll be so dissapointed in LG. & i'm so mad right now cos this is quite unexpected from a new model Home Theater system.