Camarath said:
The weapon enchantment Speed grants an additional attack which I would assume stacks with all other additional attacks (except Haste which it states it does not stack with). Are you saying that this additional attack would not stack with one (or more) granted by TWF or FoB?
No, the logic is that the FoB isn't an attack -- it's an extraordinary special ability, and hence it replaces a full attack (unlike Speed or Haste, which adds an attack to a full attack). Essentially, a FoB and a full attack are two different, non-compatible actions (which happen to look a lot alike). Like I said, the logic is a little weak..
Stronger reasoning is this: TWF doesn't give you an extra attack (look at the "Benefit" portion of the feat, not the flavor text): all it does is reduce the penalties for the off hand for making a second attack. Anyone can fight with two weapons -- TWF just makes it easier to do. The monk doesn't suffer any off-hand penalties to a Flurry of Blows; hence TWF has no effect on it (she's Flurrying, not TWF). That still leaves the door open for ITWF, though -- one could fall back on the argument in the paragraph above, that they're different actions.
Edit: I see others beat me to the second argument.
Another way to look at it is this: Anyone can fight with two weapons in a full attack action. So if the TWF feat applies to FoB, can a monk without FoB make three attacks in a round, using normal two weapon fighting off-hand penalties? But wait! A monk doesn't suffer off-hand penalties when fighting unarmed! Therefore a monk always gets one more attack with Flurry of Blows than the table says, at the FoB -2 penalty: it's her normal off-hand attack, but without the off-hand penalties she doesn't suffer! Silly monks -- they should flurry at -2/-2/-2!
