Sorry. But the first USB port has only so much power and you've lost some in the hub.
Your risk to try the next idea. Go find the PS2 keyboard to USB adapter and plug the power USB connection to that. Do not mistakenly plug the USB connection to that.
Bob
i just upgraded the hard drive in my laptop and bought an external enclosure for the old drive. it can be powered by either two usb connections or an ac adapter. however, my laptop only has one usb port, and i dont want to have to be tethered to a wall in order to use the external drive. can i use a usb hub? if not, are there other ports i can modify connections for in order to get power from them? here's what else my computer has: headphone, microphone, pcmcia (Occupied by wireless card), proprietary docking port, modem, ethernet, vga, serial, ir, and the dell module bay port. do any of these cary the same voltage as usb? if so, i could hack together a connector of my own to use its power. any other ideas?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic