Can't detect USB0_VBUS line on L-138

I can't get the OMAP L-138 to detect the VBUS active line for USB0.  I have the USB0_ID pin pulled to ground to force into host mode.  When the driver starts, the USB0_DRVVBUS line goes high, my external 5v power supply turns on, the 5vdc is present on the USB0_VBUS input pin but the driver does not detect it.  After 100ms the USB_DRVVBUS goes low and my 5v power supply is disabled.  This cycle continues every 10 seconds.

Any idea what is going on?

In host mode, do I need to toggle the USB0_VBUS input, or can I leave it at 5v all of the time?