More likely Superflower has used some inadequate components for the APFC circuit of that unit. So thanks to the shrinked APFC, that PSU woundn't be able to deliver its labeled power on 110V.
Nowadays, manufacturers do this alot. I can list quite a few PSU's that feature APFC, yet can't do their rated power on 110V:
Antec BP300P, VP350P, VP450P, VP550P, VP650P,Huntkey WD500 400W, Huntkey Silent King Win 7 Edition 300W (soon will be Win 8 I presume), Corsair VS450W.
Unlike the VP350P/VP450P, the VP350/VP450 sold in North America has no PFC.