Sad indeed 
. And strange too since in other cases PB affects some attributes of a power but not others (like the +def in Vengeance, but not the +dmg). I can't see why it should work differently with the shield 
.
CoX 50s: <ill/rad> <ice/ice> <fire/kin> <grav/sonic> <ice/storm> <earth/kin> <kin/elec> <cold/psy> <thugs/dark> <fire/dark> <dark/elec> <night widow> <EM/ninj> <mind/icy>
That's what's got me puzzled 
.
I'm *sure* there are other examples where Power Boost applies to one component but not another in a power, so it seems a weak excuse. But it's too early to remember what they are...
Well, i said it like 5 post above... u have the link to the Power Boost guide there...
Im not sure if this is true (pure speculation ahead, just trying to give an answer), but the key point could be if the BS shield could be slotted with resistance.. If so, the shield can be 'tagged' like a "defense/resistance" shield, and then it is not covered by powerboost...
In the other hand, vengance cant be sloted by +dmg (in fact, it just doesnt exist), hence it can only be slotted with +def, so powerboost would affect it.
Could this speculation be true??
Peace.
Yeah, PB will not affect beacause the BS shield adds a little toxic resistance component, and since resistance isnt affected by PB, then the shield isnt affected...
I know it is weird, that is the explanation i readed from US boards long time ago... Now with the combat log we can see it is true, sadly.
Peace.