Liteon DD-A100X - Sound Issue

Hi Guys
Just bought a DD-A100X - so far so good but have one problem.

Have it connected to my TV via Scart and the sound from DVD Discs is really low compared to watching Sky on the TV.

As an example, we watch sky at volume level 12 on our TV, at level 20 the TV is too loud ( for sky)

When we put the DVD on, we have to have the volume at 35 on the TV. :confused:

Have been through the setup and nothing seems obvious at all- can anyone shed any light on the problem I am having?

Many Thanks