NIE certifcates

I wonder if anyone can help?

In 2007, when buying a property, our lawyer obtained NIE certificates for us. These have served us well over the years when needing to show proof of NIE. They are laser printed and undated. There is a "rubber stamp" mark but one cannot tell if is original or copied.

Last week we bought a piece of land and this time did not use a lawyer, just went to the notary with the seller. All went well except that the notary was unhappy with our NIE certificates as he said they were not original. His Engish was patchy but he seemed to be saying that thre signature next to the seal is in green ink on the original.

So I have just gone back to the lawyer to ask if she kept the originals.

Her reply says :

1. The certificates we got in 2007 were only valid for 3 months. This is news to me.

2. She wonders whether the notary is asking for “Certificado de Ciudadano de la Unión Europea” 

as this is apparently "green".

3. She says I now have to go (to Caceres) to get "the actual NIE certificate" if that is what I need.

Am I right in understanding that the Certificado de Ciudadano is only dished out if I become a resident? I am not a resident and have no wish to become one - we spend 5 months or so a year in Spain.

So it looks like a trip to Caceres to get  new NIEs. I assume the NIE number will be the same. Will this certificate also be valid for 3 months only? Can anyone please shed any light, please? 

I've just spoken to the Spanish Consulate in London where my NIE was issued - and they told me the piece of paper itself is only ever valid for 3 months, although the number is with you for life.  The Consulate say the only time you need a renewed certificate is for a large purchase (house or car) so I guess that's why you're being asked for one now.  If you're a non-resident you should just be able to go to the nearest NIE-issuing police station and ask them to print you off a replacement certificate.  Alternatively, if yours was issued by the Consulate in the UK and it's more convenient, you can go there (Draycott Place, SW3)  Monday - Friday 9.30 to 1.30 and they'll issue one for a charge of £7.55.  I'll be going to London, having spent 5 hours at a police station in Cartagena and retreated, still without the required certificate!

 Thank you carmol2 for that speedy response. I now see that my old NIEs do have the date written in words in the text - "a cuarto de octubre, etc". I wonder if the new ones will have the signature in green ink. Once again, thanks.