3x Sill Plates and IBC-09

[roy835]

Section 2305.3.11 of IBC-06 requires 3-inch nominal sill plates for shearwalls that resist a load of 350 plf (ASD) or 490 plf (LRFD). This section has been removed in the IBC-09 and Section 2305 now requires use of AF&PA Special Design Provisions for Wind and Seismic (SDPWS). The SDPWS does not require the 3x sill plate for high demand shearwalls.

Is there a technical reason for this change or is this a case of unintended consequences?

Thanks.