Font size on certain websites suddenly increased

[pinkacidbootson]

For no reason i can think of, the text on some websites that i go on has suddenly got bigger. This happens on the MSN homepage, Overclockers shop website (only on the item descripstions though) and Wikipedia as well as others.
Other websites such as these forums, Gamespot and Something Awful .com are unaffected.

I have made absolutely no changes to anything on my system, so what could be causing this?

Ive also just noticed the coloured text in my sig is bigger, but when i change it to size 1 it looks the same as size 3 would usually look

 

[Barbie]

Try holding down CTRL and scrolling your mouse scroll wheel.

 

[pinkacidbootson]

Thanks, i had no idea i could do that im surprised thats never happened before actually.