Rastafarai ! I did it !
So, for those interested about scrolling horizontally with the Apple Mighty Mouse on PT9 PC version :
Download the great freeware X-Mouse Button Control here :
http://www.highrez.co.uk/downloads/X...tonControl.htm
Then, you can access the settings of all your mouse.
Create a profile by clicking "Add".
Then go search the "protools.exe" launcher.
In the settings "Tilte Wheel Left" and "Tilt Wheel Right", go to : Simulated Keys (undefined).
We're gonna define it !
Enter in the blank this for the left wheel : {CTRL}{SHIFT}{MWUP}
and this for the right wheel : {CTRL}{SHIFT}{MWDN}
By scrolling horizontally, it will emulate the CTRL + SHIFT + WHEEL.
Then apply, and go enjoy your horizontal scroll in PT ! :)
ps:
Maybe I'm wrong, but I think PT9 PC don't understand the horizontall scroll of mouses... I've tested it with a Logitech mouse (one like grendizer mentionned before) and it doesn't work.