If you built your smelter from stone, rather than stone blocks, is there any chance you've forbidden the type of stone used to build the smelter, using the stocks menu? Forbidden workshops can't be used, which would explain the manager's work orders not working. Not sure whether forbidding non-economic use of the type of stone in the stones menu causes that issue as well or not.
When you say your smelters are not in a burrow, do you mean your furnace operators, or you smelters (the workshops)? The smelter bug (if the theory that burrows are involved is accurate) is with smelters being in a burrow, but not all ingredients being in the same burrow as the smelter, not with the workers being assigned to a burrow (in which case, the jobs not being able to be completed wouldn't be a bug). ((aside: Could Toady One have gold-plated the code for smelting jobs by trying to prevent the player from queuing jobs that couldn't be completed by dwarves assigned to the burrow that the smelter is in? That's the only explanation I can think of for burrows causing you to not be able to schedule the jobs.))
On the other hand, could it just be a range issue, like with butchering jobs? For at least some workshops, the workers will only go so far away from the workshop to look for inputs; the smelter may require flux, fuel, and ore to be nearby for a job to be queued. (That would mean the manager jobs work because they somehow select ingredients differently, or because the manager only cares whether the inputs needed exist when they OK a work order, not whether they're close to the smelters.)