V+ Volume problem

[Grogboy]

I recently had V+ installed and have the sound through my panasonic SC-HT880W home theatre system.

Last night i listened to DVD's for the first time and when i turned on the TV today the sound level dropped on the home theatre system after about 10 seconds.

I have to turn the system almost to full volume now to hear the TV.

I tried listening to the tv through the Scart lead rather than the HDMI and the sound level was back to normal.

Put it back on the HDMI and again it dropped approx 10 secs after re-booting the V+ box.

The problem is that occasionally, (eg when playing about with V+) the volume suddenly jumps back to normal for a split second defeaning myself and my neighbours !!

I've adjusted all the sound settings on my tv, sound system and tried the various settings on the V+ box, but haven't managed to sort it.

Have tried Virgin but they dont seem to have the answer or reason why me using my DVD has affected the volume settings on V+ via HDMI.

Any ideas/ help much appreciated, and sorry for waffling - i'm not very technically minded !!