Auto-scroll mystery

Recently I've had this strange auto-scroll thingy happenning with almost everything I do, causing me to make typos, all sorts of other problems, etc. At first I thought it was a Google Chrome issue, or a Firefox issue; but it also happens when I am offline working on say a WordPad doc or similar, so I'm thinking it's a Windows 7 issue.

I thought of disableing vertical scroll in Mouse Properties, only I don't have this option in the first place :o. Anyway, how do I stop this auto-scrolling...

 

Thanks Cee. That almost hits the nail on the head -this is the other thing I was thinking of, but my middle button is a mouse wheel which can also act as a button if you press it (fairly standard...), only I'm fairly certain that I'm not actually pressing the mouse wheel when these arrows/symbols and the auto scrolling starts happenning. Maybe when I left-click, this is somehow ghosting the middle button, but no idea how I can get round that Maybe I need a new squeeker :)

 

It was the mouse that was faulty, so I got a new one and all is OK now...

 

Yes, the mouse squeeks just fine ;)

 

What is what lol!

 

As the MCP said in TRON, end of line...