Probably caused by XYZware, which has good but not great slicers. Try Slic3r.
After that, the print might still fail, and it's a common problem for all 3d printers.
if your object is smaller than the margin of error of that printer, then it will be very difficult to product that part.
Also, because of the nature of heating plastic of all 3d printers, if the part is too small, and the printer keeps racking up layers without the previous layer cools down sufficiently, the print will be too soft and friction of the nozzle will drag your print all over the place.
One work around, just as ShadowWizrd posted, is to import 2-3 of the identical parts at the same time. This way, when the printer is printing object B and C, object A can have some time to harden a little.
and FYI, always save your STL file with one object and then import multiple STL files using XYZWare. If you include multiple objects in a single STL file, Da Vinci will act funny and build in order of objects instead of layers, meaning it will create an obstacle for itself.