cause of this problem is, that interface "lo" is not properly deconfigured on system shutdown. Thus, "lo" won't be properly configured on system bootup. /etc/network/run/ifstate has to be deleted on system shutdown by /etc/init.d/ifupdown-clean. The link from /etc/rcS.d/S18ifupdown-clean to /etc/init.d/ifupdown-clean is missing.
You can add this link for proper function, or - if You dont know how to do this - just reinstall ifupdown via apt (--reinstall). This will fix it, too.
Klaus Knopper is already informed of this problem and will fix it in the next installer.