No burrows active? What do you mean by "active?" I'm pretty sure it doesn't matter if they have citizens in them, if a non-alert burrow encompasses a workshop, that workshop's reactions are limited by what reagents are in the burrow. For example, I put my garrison in a burrow, so I could make dwarves go there right away for military training. As soon as I put it in a burrow, before adding any dwarves, the workshop became unusable, as no coins were accessible. When I put a coin stockpile in the burrow, and it filled up, the garrison jobs became white again.
Edit: my trade depot is one floor above my trade warehouse, and it works no problem, so the warehouse does not need to be on the same floor.