Ok, i run some test, found some tricks, have few questions, but i'm glad...
bitpim works on this phone, but only for system files, i can't access to other features, but it's enough to save the sms files. The sms are located in the folder called "User" at the root directory. You have to save the folder "Msg". after flashing just restore this "Msg" folder. Be careful, respect the tree directory. It seems that all the files in User directory can be used to have the same settings in the mod FW than the old FW.
Rather use Bitpin than tk file explorer because bitpim can see more files and so more settings (i first used tk, and some files didn't show).
Then i tried to export my phone memory contact in the mod FW, and then the phone always freeze. It happens with the "phonedb" stored in the "db2" folder at the root directory. It seems that i can save the message error in a dump file or something like that (phone displays 12 screens about the issue). If you know a procedure to get it i'll upload the dump for you. Phone also freeze when i trie to access to the phone in usb mode using phonedit forensic.
To bypass the freeze, i flash the phone again (when i upload the phonedb, not with the usb freeze). I did three times!!! then i found that i just have to take the battery off and take the sim off, then replace the battery, turn on the phone and when sim is asked put the phone in qualcomm usb driver, run bitpin and replace the mod db2 folder (prior to the manipulation, save the mod bd2 folder with bitpin).
Last thing; when i tried to set a password for the phone, old password is required may be your password... how can i do to delete it and set a new one?
Thanks in advance. And sorry for my english feel free to ask more precisions.