Samsung 50" Plasma has high bit error levels?

We've just bought a new Samsung 50" Plasma TV (PS50B530S) and when i tried to plug it into the antenna thrught the socket in the wall, it does not come back with images. All the channels were found during the scan but no images come back (or distorted and laggy images). Tried to check the signal it was recieving and nearly all channels have approximatly:
Bit Error Level: 6-7
Signal: 40-60

I've tried to plug in my freeview box that i have had for my old tv and it works fine with the same connection.

Also tried to plug in a cheap antenna to the tv and that works perfectly with low/no bit error at all.

Can anyone help with this problem??