Runaway scrolling

Hi Everyone!

I've run into this situation while looking at pages on the internet. I'm using the Safari Browser. I will be scrolling down the page one click at a time and all of a sudden, the scrolling will take off by itself and run down to the end of the page. Any suggestions?

Also, when I am reading something, the screen will dim after 30 seconds or so and I need to either refresh it or keep my hands on the touchpad. Is this normal?

Thanking you all in advance for the help.

Are you scrolling with your mouse, or with the trackpad?

The screen dimming can be turned off under the "Energy saving" System preference pane.

I am scrolling with the trackpad.