and..
Pinch to zoom DOES work in gallery..
NOW, this is my (tested just now) theory ONLY..
On X10, we were given only Mediascape to view Music, Vids, Photos..
Viewing photos thru M/Scape, pinch to zoom DOES NOT work.. movement of a finger scrolls to next image..
I have installed the GALLERY .apk to my X10, for access to vids and pics thru the native, standard android gallery app (ie, does NOT go thru M/Scape), and when viewing images thru GALLERY, pinch to zoom DOES work.
(I do not recall where i read of/found/downloaded "x10i_GALLERY.apk", however it was here, or xda, or XperiaX10Forum..)