[U-Boot] USB ethernet on Panda

I just built U-Boot 2012.04 for the OMAP4 PandaBoard, hoping that the USB ethernet would work. Sadly, it does not - the board hangs during the initial USB scan:

U-Boot 2012.04 (Apr 30 2012 - 18:08:55)

CPU : OMAP4430 ES2.2 Board: OMAP4 Panda I2C: ready DRAM: 1 GiB MMC: OMAP SD/MMC: 0 Using default environment

In: serial Out: serial Err: serial Net: No ethernet found. Hit any key to stop autoboot: 0 Panda # usb start (Re)start USB... USB: Register 1313 NbrPorts 3 USB EHCI 1.00 scanning bus for devices...

At this point, it's dead - ^C does not work, nor does the RESET button.

Any ideas how I can get this working?