Not sure if this makes sense, but...

If I have the weight value = 0 for a product, it tells me UK Postcode (Parcel To: (1 x 0.00Kg)) £1.39... which makes sense, but as soon as I put any other value in it reverts to (0 x 0.00Kg)) £0.00, even will a high ratio of 250 in each shipping table.

btw it is also doing it in checkout as well as shipping estimator.

Will play around a bit more, but let me know if you now something extra,

Thanks,
Jay