I noticed that while using Opera cursor dissapears from time to time. It never happened to me before. I used some Antivirus software but noone finds nothing.
Anyone had similar expiriencecs?
Viruses don't usually do things like that, they'll either do nothing, or break things, but they don't make cursors disappear after a while of using Opera. It's probably some problem with your version of Opera or your mouse drivers, or something of that sort. Try updating/downgrading Opera or seeing if it happens if you use a different browser for a while.
I once had a virus that causes cursor to fall of the screen. You don't know what crazy ideas that idiots that make viruses have.
edit
yes, it was VIRUS!