Greece 20 Euro cents 2002 with both Madrid and Athens mintmarks

The link for the coin in question is:

N#117

I have one example of this coin in my collection, which I picked up from change during a visit to Europe. 

I just noticed that my coin has mintmarks for both the Greek National Mint in Athens (flower symbol between and a little bit to the left of the two stars immediately above the date) and the Royal Spanish Mint in Madrid (an incuse “E” in the star immediately below the date). 

Is this normal?

The only picture of this coin on the Numista webpage appears to be an Athens mint only product (it has the flower mintmark, but no “E” on the star). There are no pictures on the page for a Madrid mint coin, so I don't know if my coin is an example of what they should look like, or if it is some kind of error (because it has both mintmarks).  

Does anyone know if the Madrid Mint coins have both mint marks (and if so, why)?

They are all like that. Not sure why. Maybe some of the dies made were sent to the Madrid mint to use. The same occurs on all the other 2002 coins with either S for Finland or F for France.

Hi !

The capacity of the Greek Mint was not sufficient to make all the coins needed, admission of Greece in the eurozone was quiet a surprise and Greece was not ready. So part of them where made by France, Finland and Spain.

2 € and 1€ made by Greece (without letter) or Finland (those one get a “S” for Suomi in the star), 50 and 10 cents made by Greece (without letter) or France ( a “F” in the star) , 20 cents made by Greece (without letter) and by Spain (a “E” for España) …

None of them are rare. All made by millions !