Breda,
I noticed that too in your log. In your /etc/config/dhcp file, change it to this:
config dnsmasq
option domainneeded '1'
option boguspriv '1'
option localise_queries '1'
option local '/lan/'
option domain 'lan'
option expandhosts '1'
option authoritative '1'
option readethers '1'
option leasefile '/tmp/dhcp.leases'
option resolvfile '/tmp/resolv.conf.auto'
option localservice '1'
option logqueries '1'
option rebind_protection '0'
config dhcp 'lan'
option interface 'lan'
option ignore '1'
config dhcp 'wan'
option interface 'wan'
option ignore '1'
config odhcpd 'odhcpd'
option maindhcp '0'
option leasefile '/tmp/hosts/odhcpd'
option leasetrigger '/usr/sbin/odhcpd-update'
Just copy and paste it over, save, then reboot: reboot -f
Running the latest OpenWrt stable release