Question:
Please, read the post of Aztec on this thread:
/showthread.php?t=193870
Perfectly put into words and I am glad he allowed me to use his post for our Guerlain Week on the Women's Forum.
There is also a photo there from the 'old' Chamade pour Homme bottle.

Answer:
I just bought the re-issued Chamade pour Homme from The Institute in Paris. On many websites it is falsely marked as an EDP, but it IS an EDT. On the phone the Guerlain SA confirmed that it only exists as such and never has existed as EDP. It doesn't last as long as Derby but still has some potency after, say, 6 hours.