It seems the problem is solved now, Raider.

This morning I was checking out the wheel of my mouse and, after some touches, the horizontal zooming appeared suddenly. I'm still wondering what happened.
This is how Acid looks like at the moment:
I can't understand why zooming didn't appeared the first time I ran the programme. I'm thinking about a bug or something like that.
Many thanks again for your help, Raider. If I hadn't check the wheel I'd be still trying to find out what happens.
