it didn't come with any instructions saying what the extra wires are for?
as for your DVD drive issue, I assume the drive is USB-powered (no separate power wires)? it sounds like it's not getting enough power with the wires extended. if this is the case then you will have to give it a separate power source.
does the drive have a power input jack? if it does then you can use a point-of-load regulator or run power wires from your PC's power supply (M1-ATX) to give it direct power. if it only has the USB input then you would have to plug it into a powered USB hub (you would have to provide power to the hub in the same way).