[Galaxy S III Q&A, Help & Troubleshooting] ScratMan38:
I made some trials to understand why this phenomenon happens.

First I started with a backup of my actual ROM (ArchiDroid 1.7.9 based on Samsung NA7) and the content of my internal memory and SDcard.

Then, I tried to install the latest official 4.3 ROM for my version of the Galaxy S3 (code FTM, branded by Orange) : the firwmare is ML2.

I downloaded it and flashed it with Odin 3.09. I had the surprise after reboot to find my apps and parameters... I thought Odin would erase everything, but no, it has left everything.

So I made the test :

** Stock official Samsung ML2 : S-Voice fails. If I tell "her" to send a message, she asks who to send the message to, I say "François Dupont" (name has been changed), she writes "François Dupont" after the speech recognition, and stops.

So I made a factory reset, wiping data, internal memory and sd-card, entered my account, wait for the syncs to end, and started again :

** Stock official Samsung ML2 after full wipe : S-Voice fails. If I tell "her" to send a message, she asks who to send the message to, I say "François Dupont" (name has been changed), she writes "François Dupont" after the speech recognition, and stops.

So I decided to return to ArchiDroid 1.7.6 (based on ML4).

I flashed recovery through Odin and installed ArchiDroid 1.7.6, making a full wipe again, and test again after end of syncs :

** ArchiDroid 1.7.6 : S-Voice works perfectly. If I tell "her" to send a message, she asks who to send the message to, I say "François Dupont" (name has been changed), and after the speech recognition, she asks to select the phone number I want to send the message to, then requests the message to be sent, and proposes to send it.

I continued the test by installing ArchiDroid 1.7.7 (still based on ML4) over 1.7.6 (no wipe, using previous preset, only used the forced update mode of ArchiDroid installer).

** ArchiDroid 1.7.7 : S-Voice works perfectly. If I tell "her" to send a message, she asks who to send the message to, I say "François Dupont" (name has been changed), and after the speech recognition, she asks to select the phone number I want to send the message to, then requests the message to be sent, and proposes to send it.

So I continued the test by doing a backup and installing the ArchiDroid 1.7.9 (based on NA7) over 1.7.7. Strange thing is that it could not use my previous preset, I had to recreate it.

** ArchiDroid 1.7.9 : S-Voice fails. If I tell "her" to send a message, she asks who to send the message to, I say "François Dupont" (name has been changed), she writes "François Dupont" after the speech recognition, and stops.

I wiped everything, and restored the backup of 1.7.7, reboot and again :

** ArchiDroid 1.7.7 : S-Voice works perfectly. If I tell "her" to send a message, she asks who to send the message to, I say "François Dupont" (name has been changed), and after the speech recognition, she asks to select the phone number I want to send the message to, then requests the message to be sent, and proposes to send it.

I then tried to make a TB-backup of the ML4 apps (contacts, phone, s-voice and messages) and install the ArchiDroid 1.7.8 :

** ArchiDroid 1.7.8 : S-Voice fails. If I tell "her" to send a message, she asks who to send the message to, I say "François Dupont" (name has been changed), she writes "François Dupont" after the speech recognition, and stops.

I then tried to restore the different apps backup I had from ML4 and rebooted, but no way, S-Voice is still broken.

So I'm going to use ArchiDroid 1.7.7 for the moment.