Now I've just changed to 1280x960 resolution, (I think) the max supported by VL on this monitor.
I expected all 1280 options to be at the same place, but this is somewhere below in the 'display settings' of the settings manager. One would expect the things to be sorted and displayed (or did I mess up with the xorg.conf?).
Now things don't seem elongated (but this is less than the best fit written in my monitor manual i.e. 1440x900)
Actually, common sense says that the second parameter in resolution should not exceed 900. All these days I was using 1280x1024. 1024 > 900 (the best fit) so obviously the screen would be elongated horizontally (correct me if wrong).
I feel stupid
all these days I was living with the issue
and just now I've fixed it.