Failed to obtain MAC address

[Epco Dijk <epco.dijk@gmail.com>]

Hi,
I try to install debian on a QNAP TS-219P using the procedure on
http://www.cyrius.com/debian/kirkwood/qnap/ts-219/install.html

Everything went fine until I try to run sh flash-debian.

It immediately returns
Failed to obtain MAC address

ifconfig returns:
[/tmp] # ifconfig
eth0      Link encap:Ethernet  HWaddr 00:00:00:00:05:09
          inet addr:192.168.1.234  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST NOTRAILERS RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:10358 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6683 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:532
          RX bytes:12000290 (11.4 MiB)  TX bytes:1841484 (1.7 MiB)
          Interrupt:11

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:46 errors:0 dropped:0 overruns:0 frame:0
          TX packets:46 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:12362 (12.0 KiB)  TX bytes:12362 (12.0 KiB)

Which is the same MAC-address as in the script.

What can I do to solve this?

Thanks in advance.

Epco Dijk