You could try powering it with +/- 5V rails. The Arduino will take more current from +4.5V than the splitter chip can provide I think.
Alternatively power Arduino separately, the 0.5V difference shouldn't matter because the circuits controlled have resistors that will limit the current, some have diodes as well which will lose 0.6V or so anyway.
It ought to be possible to redesign the circuit using rail-to-rail opamps to just run off 0..5V, but that's a lot more ambitious.