Salut Jean,
I can say my Adword account is link to G.A. because my campaign ''filtre fournaise_2'' has 359 visitors...
Do you manually tag your campaigns? As per Analytics support and from experience, human error in tagging is often the most common source of errors:
- Auto and manual tagging are being used at the same time
- Manually tagged URLs are missing a parameter
I recommend you use auto-tagging otherwise you will spend hours of entertainement coding urls for each kwd... Fun, Fun, Fun
You do have gaq.push(['_trackPageview'] so I doubt this is the cause of the error and since it's a big commerce site, I can only assume the code will be implemented at a template level.
Hope this help.
Cheers,
Freddy
P.S: if you feel like being "stalkish", remember to update your GA code for Remarketing