Problem with ifconfig

[TR <tony@the-sphere.org>]

I am having some problem that I don't understand with ifconfig:

tony@debian:~$ /sbin/ifconfig     
: error fetching interface information: Device not found

However,

tony@debian:~$ /sbin/ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 00:80:AD:09:86:ED 
         inet addr:192.168.1.101  Bcast:192.168.1.255  Mask:255.255.255.0
         UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
         RX packets:26802 errors:22859 dropped:0 overruns:0 frame:0
         TX packets:8332 errors:2 dropped:0 overruns:0 carrier:2
         collisions:0
         RX bytes:14273909 (13.6 MiB)  TX bytes:1214357 (1.1 MiB)

I am under the understanding that ifconfig when given without additional 
parametrs should show the configuration for all devices. What could be 
wrong?
Thanks.