@Bazza,
Is it an LCD TV?
The majority of LCD (and possibly plasma) TV's dont accept the standard Amiga scart output signal (picture is corrupted/distorted/never shown properly), which is a non-interlaced signal, the majority do recognise an interlaced signal but unless you can specify the softwares screen mode you will have the same problem.
They will recognise signal put out by the other 2 ports but the picture quality isnt the best.
Although you could be one of the lucky few who hae a TV that can accept non-interlaced pictures (unfortunatly I am not which makes me sad :-( )