The bees hadn't touched it when I checked so I smelled it and had a drop. It smelled like rotting fruit and tasted the way I'd immagine rotting fruit tastes. Basicly, it didn't taste sweet, and it didn't smell sweet. Yes, this stuff was exposed to sunlight.
Nathan, Could this smell be fermentation? If so, and you wanted to keep the sugar syrup you could reheat it. Heat it to above the boiling point, a rolling boil 2-5 minutes. this should make the syrup usable.