Most games these days have bugs, glitches or problems. So it should come as no surprise that a game as open and varied as Fable 2 has its fair share. There are two major bugs in the game which can impede your ability to even complete it, and there are two glitches which help you become more rich and powerful.
The first bug is during the Abbot's quest when visiting the Temple of Light in Oakvale. If during the quest speech you walk away from the Abbot, you'll be unable to actually achieve the quest and therefore unable to complete the main story line. The second bug occurs during local co-op play. If you join a game during the childhood phase and select an already existing save to base the henchman off of, your save will lose all XP and Gold. Ouch! Both bugs are known and Lionhead is working diligently to correctly both issues.
As for glitches, well there are two of these also. The first one is simple and obvious; and it will yield you a TON of gold. All that is required is that you invest in a few shops and properties. Save your game, go to your system preference and change your clock to something far in the future. Go back into the game and presto - mucho coinage. The second glitch involves co-op play, and will yield you infinite experience. During a local co-op game bring a henchman in without being assigned to a profile. Then go to the henchman's abilities and discard them all. Immediately have that player leave and all that experience gets transfered to the hero character.