SIOCADDRT: Invalid argument

[Daniel Pérez Pérez <danito.perez@teleline.es>]

    I use Debian 2.1 and I have changed my Kernel 2.0.36 to 2.2.4 and
when I use the command route, for example route add -net 127.0.0.0 I get
the message SIOCADDRT: Invalid argument. I use an ethernet SMC ultra and
it works fine, even when I get that message. The configuration of the
Kernel is OK. I would like to know what is going on.