if usbf don't reconnect after a resume, you can workaround the problem by creating two scripts.
The first one in /etc/apm/suspend.d , I called it 99usbdown.
his content is:
------cut here ----
#!/bin/sh

       ifdown usbf
       rmmod usb-eth
       rmmod sa1100usb_core
exit 0
------cut here ----
The other is in /etc/apm/resume.d, I called it 99usbdown ( too, but shouldn't be important 
his content is:
------cut here ----
#!/bin/sh

modprobe usb-eth
exit 0
------cut here ----