Thanks so much all. You wouldn't believe it... DH went down to local baby shop to 'research' and came back with an Oricom one. The man cannot help himself, he just has to buy stuff! Good sound... haven't checked out the range yet.

While he was gone, I'd gone looking (again) for the receipt for the TT one and managed to find the manual - still no receipt. AFTER he set the new one up I called the helpline number on the back of the manual and after a quick chat, the lady just said "hmmm, well it really shouldn't be doing that. Just send me a photo as proof of purchase and I'll post you a new one." WTF???! Awesome!

So now we have a lovely new monitor that we don't really need...
Thinking we might keep it though as the one we use for DDs room has terrible static.

Thanks again for your feedback. For the record, I can highly reccomend TT for their excellent customer service!