Well it was an interesting resolution in the end.
Yes it was called from rc.M, inside an if construct can't remember the exact syntax....
Anyway I comented out the if part, and the next time it ran it came back saying eth0 device not found!!
Then I was told I could run custom scripts from rc.local, so I did this:
modprobe 3c59x
ifconfig eth0 192.168.1.21 netmask 255.255.255.0
route add default gw 192.168.1.1
and added that script to the rc.local file.
Now everything runs smoothly
But cheers for the feedback!
PS: yea it was executable to start with too