Crash you make a good point, I never really thought about it as two totally separate circuits.
With that being said I agree with Wacked that the answer may lie in the definition of a circuit as it applies to the CEC.

This excerpt from the 18th edition handbook may help to shed some light on the intent of the rule, I think the key words here is "All circuits AND apparatus"

We intend that all circuits and apparatus also be provided with manually operable control devices or disconnects that are capable of disconnecting all ungrounded conductors simultaneously at their point of supply. However, we intend that multi-wire branch circuits that supply only fixed lighting loads or non-split receptacles be allowed to be controlled by separate single-pole disconnects in each of the ungrounded conductors of the circuit. In this case, we intend that the loads be connected only to the neutral and one ungrounded conductor (see Figure 14-010).

Last edited by bigrockk; 11/01/07 11:56 PM.