Watching TV while recording DVD

Hi all,

Sorry if this is an extreme newbie question, but I’ve had a search of the forums and can’t find an answer…

My dad has recently bought the Liteon LVW-5045, and he’s set it up as follows (sorry if I do not have the right cable name);

Aerial from wall to DVD
Aerial from DVD to TV
Scart from TV to DVD

We can record from the TV fine, but whilst it’s recording, we can’t watch TV on another channel. We switch the TV from AV to TV, but all we get is the sound of the channel we choose, but the picture of what’s shown on AV (the channel the DVD is recording) - but scrolling left / right, and slowly moving up / down.

This is also the same on the setup I have with the Pioneer DV-350.

Is there something wrong with the way we’ve set it up, or is this a drawback of DVD players?

Thanks for your time, in advance.