Marco ! carajo, the error is corrected.. I realized that after boot..that I don't have any "lo" interface up! (with ifconfig) Wierd! I checked the file : /etc/network/interfaces, and it was ok :
auto lo eth0 iface lo inet loopback iface eth0 inet dhcp
It seems that /etc/init.d/networking start does not perform well.. After boot..only the eth0 is up. And sometimes, nothing..In those cases..I was performing a : Musix -->Programs -->Knoppix -->Net-->network card configuration. Then, surprising, again only eth0 were up. Still no loopback. So I checked the /etc/init.d/networking script..and saw that the restart option does not make a ifdown of the loopback.. I checked the execution of /etc/init.d/networking restart , and SURPRISING, still no loopback after..I suppose that Musix -->Programs -->Knoppix -->Net-->network card configuration use that script.. So I executed myself an : ifdown -a and after an ifup -a.. And : WOUHOU..eth0 and loopback are there... !!! AND ALL APPS ARE WORKING !!!! Hmmm..for now, I'll put ifdown and ifup in an init script..so I can finally play with Musix. Do you have any idea for the strange behavior? Thank you for the strace tip ! Julien.