Once again - please USE OUR HINT and check what is waiting time for translations. It doesn't matter do we think that translations happens or not - is matters do they really happens or not. So please use our hint and VERIFY that you really do not have any translations there what is hard to believe for us now. If it do not happen right now you can temporarily disable cache and you will see again how it works when cache is not filled up. We do not believe that you have 8 sec longer page generation without any translation - it simply doesn't have nay sense. We believe that there are translations and you just do not realize it. And we already gave you long time ago tool how to verify it. Please use it. Without verification future discussion has no point, because we do not know what we discuss about. Please use our hint and verify translation waiting time on page where you think that translation doesn't happen. If it really doesn't and generation is slower then we will look closer on this. Right now your question has no sense, because it is not confirmed that there is no any translation.
CSS issues for Admin CP -> vBET -> Translation Options -> Translation response time ON doesn't matter at all. As you can read in parameter description this is visible only for administrator and should be used only to determine what is going on downstairs. Please use it - give us results (how many waiting time for translation is on this page where you are waiting 8sec for generation, how many connections) - and turn it off.
We are not able to help you when you refuse our help. Please use it.
About French message - please give EXACT message (title and content) posted in French so we will be able to test it and solve the issueBut do it in separate thread - this one is about your waiting time differences. We will be lost if we will split one thread by several issues - no discussion tracking will be possible in such case. Sorry for this little inconvenience but it will help us all to find out on what stage the issue solving is.