>>If you press the Ctrl key and scroll the mouse wheel it will have this effect.
>
>That was it. Do you know if there is a way to cancel that possibilty so it would never take effect in the first place?

Sometimes keyboards get sticky keys, so one of the Ctrl keys stays stuck on even when you think it's off. If you don't want to buy a new keyboard here's what you can do:

- lay a piece of newspaper under your keyboard
- turn your keyboard upside down and vigorously hit the underside of the keyboard a bunch of times
- you will probably see staples, paper clips, bits of paper and disgusting bio-junk fall out onto the newspaper
- then vacuum the keyboard to get out the dust

If you've got a keyboard you like, and want it to last a long time, get in the habit of covering it when you're not using it. That way, no dust gets in and it lasts a *lot* longer.