Check the USB hub properties and make sure it's not set to go into sleep mode.
I would also avoid using any powered hub for stuff like this anyway and use sockets on the mobo instead even if you get a PCI slot USB card.
IL2, FSX, ROF, SOW, Cliffs of Dover...
Vista Ultimate 64bit. Core2Quad9550 @ 3GHz, Nvidia 560Ti 1GB @ 1920x1080P, 4GB RAM, Creative SB X-FI