Mask posted not too long ago that Weave entries fire when the regular spells are on Global Cooldown. I read that to mean not individual spell cooldown, but global cooldown, like the spell system in general. It is best for AA's, insta-clickies, and near instant summoned items from mage (which is the way I use it). I weave in 2 summoned items (Blazing Orb & Icebound Sliver) and I see them fire a lot.