I flashed the CW recovery 82 times on my Galaxy S Duos with no success rooting it. It seems that someone posted bad instructions that were copied all over the net. to The instructions stated to hold vol-up, home, and press power to bring up the CW recovery after flashing, and removing and re-installing the battery. 
Holding vol-up, vol-down, home, and pressing power after flashing, removing, and re-installing the battery actually works every time.
On the 83rd attempt my phone was rooted.
Cheers
Holding vol-up, vol-down, home, and pressing power after flashing, removing, and re-installing the battery actually works every time.
On the 83rd attempt my phone was rooted.
Cheers