Nice website Fumanchu ! I didn’t see the announcement in french but then again maybe I missed it

It would be nice to list it in our french section
Now, about the validating...
I have said this elsewhere a few days ago : I don’t think going for strict validation is a goal in itself. Now don’t make me say what I didn’t say : I am pro-standards and a valid code is certainly better than one which does not validate.
My perspective is that of someone who builds website professionnally. More often than not, clients will want the the best fitting design and features... and won’t care one bit about validating until you take some time to explain how it maximize their investment (Jeffrey Zeldman’s book come in handy for this

). So far, so good : I have found translating web standards into business terms convince 90% clients of the benefits of standards.
Then, there is something we freelance webdesigner or agencies have to take into account : the competition is fierce and for us to sell on such a market requires we don’t blow up prices too much. Otherwise you end up with few (or no) projects (unless you’re a famous webdesigner and get a bonus for reputation but not everyone is John Hicks).
It also means that if you want to make a profit, you can’t afford to spend too long a time building a website. I don’t say that you have to build websites "quick and dirty" that’s not how I see things. But it’s a balancing act between satisfying the client (and for me it means : satisfying the end user) and sticking to the standards. Frankly, if I have to use a few CSS hacks to cut down dev time and get a few errors, so be it (as long as it’s not key design errors) ! If the client wants a complex design which validates and works the same with all browsers, then they’ll have to pay extra and be aware it can take a bit more time.
I am not saying creating standards compliant website takes more time on the average, but that in some case (complex design), it can be tricky and costy to achieve compliancy...