Hi guys, I'm hoping someone can help me wiht the issue I've been having, as it's driving me up the wall!

Just before Christmas I bought myself the Sony BDVEF200 home cinema system, to give myself a nice upgrade to the lacklustre sound performance from my Samsung LE40D503.  If it's relevant at all, I get my cable TV service from Virgin Media, and am currently using one of their HD Tivo boxes.

All hooked up in the usual way, tivo box goes into one of the Sony unit's HDMI inputs, and then the Sony output to a HDMI slot on the TV.  Fantastic.

All is well and good when playing DVD's and BluRay's, the sound is fantastic.  Same goes for any regular non-HD channels through the tivo box.

The problem occurs on numerous (I'm yet to try them all) HD channels however.  When I first switch to any of said HD channels, everything seems to be normal.  The sound works perfectly, all is good.  The oddity occurs when whatever programme I'm watching goes to a commercial break.... the sound cuts out completely!  Changing channels on the TiVo box does nothing, the sound remains muted on all channels from this point onwards, and the only resolution I'm left with is to turn the Sony unit off completely and back on again, at which point the sound springs back to life.  It's also worth note that if I simply leave the box switched on, and wait for the commercial break to end, the sound does not come back.

To make things even more strange, when this problem occurs and I then have to turn the Sony unit off and back on to recover the sound, it's almost as if the unit has partially frozen up, as when I press the power button on the remote, the "standby" messages starts flashing on the LCD screen, as you would normally expect, but this message then persists for upwards of 2-3 minutes, and I'm unabl;e to turn the unit back on again until the message has disappeared!

I've got the box connected to the internet via a hardwired cable to my router, and as such I've run the software update function, the first time this actually applied some updates, the second it seimply told me that the software was 100% up to date, but I wasn't sure if this included the firmware as well, as I've read about some similar issues with Sony TV's being fixed by updating firmware.

Any answers/suggestions would be greatly appreciated, I'm a bit lost if I'm honest!  It isn't the end of the world, as I'm still able to watch regular definition channels fine, but I'd prefer to be able to watch the HD ones too, but having to switch everything off and back on every commercial break is just too much hastle!