USB Ethernet stop working after hotplug

I have found that my Apple USB Ethernet dongle stop working if I plug in another USB device. This happens both using a USB hub, and when plugging directly into the MacBook Air. I also see this problem when using a similar dongle from another supplier (called AX88x72A). The USB Ethernet dongle works fine after booting, with status "Connected", but if I plug in another device like my phone or a USB drive, the status changes to "Cable Unplugged" after a few seconds, ifconfig no longer show the en1 interface, and syslog gives a few error lines such as:

Fri Jan 13 13:17:19 Airbook-II kernel[0] <Debug>: en1

Fri Jan 13 13:17:19 Airbook-II kernel[0] <Debug>: Ethernet \[AppleUSBEthernet\]: Link down on en1

Fri Jan 13 13:17:19 Airbook-II kernel[0] <Debug>: AppleUSBEthernet::prepareForFlash - Link down, Device 87bf600

Fri Jan 13 13:17:19 Airbook-II kernel[0] <Debug>: AppleUSBEthernet::prepareForFlash - Link down, Device 87bf600

After this, I must reboot the MacBook Air to get the dongle working again. Do anybody know how to force the AppleUSBEthernet driver to rescan the device tree (or something similar)?

With regards,

Birger Retterstøl Olaisen