When using my USB hub, the iMic disappears! (Mac and PC)
Every manufacturer of USB gear wants you to plug their product directly into the computer, and they usually state the device may or may not work well with all USB hubs. In general, the way to troubleshoot hub problems is to remove the hub, make sure the device is working, and then reconnect to the hub. Generally, a powered hub (which has its own AC power supply) will work fine.