Why have my posts started adding URL tags around links
 

My old links were working fine but now they look like this

Chain Reaction Cycles [URL="http://www.awin1.com/awclick.php?mid=2698&id=117986"]www.awin1.com/awclick.php?mid=2698&id=117986[/URL="http://www.awin1.com/awclick.php?mid=2698&id=117986"]
Good for just about anything including swim and running gear
FREE delivery on all orders over $99

Also how do I get into a proper html editor instead of the advanced editor so i can paste in affiliate banners without using the add image dialogue box?