Thank's for clear reply 

I guess that's the reason why you picked unwrapped
The reason was i have to much problem for my connaissance, forum was slower,
and somme css instruction from original forum theme was looking different,
i tried resolve this problem several hour this make my crazy lol and i decide i wil never hear from wrapped or iframe etc..
Wrapped is perhap's à easy solution for people who kan play css and php for correcting the theme but it's not my case, the only think i wisch is that the member are correctly shared an the two systeme it's all
Another big reason is when you wrappe the forum you must disable personel user choice for theme and this is not so fear

For solve my problem i have to find who the user must register and login,
for all it's ok in dual system... and not deconnecte when changin page or other

When user registred or login only in smf, there must obligatory login from mambo box if not there are no recognized in mambo this is the problem ...

I think "in  my case" and perhap's others, one solution is perhap's this:
Taking the original smf link for registred, forget password, etc in your boxe this will open the corresponding page from forum, and then after this force the user to connect in your boxe at the front site, (this is esay to take only remove the buton from smf theme )
This will then solve the problem...

I trie to modifie your "mod_smf_login.php" for this but my knowledge  in php is not good enought :/

When you (or sommwere) have little time i whel big happy you say me ho i can modifie this in your file

I hope you are good understand my english perhaps i can end up whis this solution