On some systems dnsmasq is not getting to run, even though configured

[Chris Green <cl isbd net>]

I have three systems here all running Ubuntu 12.10 (well, one is
Lubuntu, one is Xubuntu and one is just Ubuntu but that shouldn't
matter).

On one (a 32-bit one) the default configuration of Network Manager
running dnsmasq works exactly as it should and /etc/resolv.conf is:-

    # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
    #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
    nameserver 127.0.1.1
    search zbmc.eu


On the other two (both 64-bit systems) although configured to run
dsnmasq from Network Manager it fails to run.  Their resolv.conf file
is:- 

    # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
    #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
    nameserver 192.168.1.2
    search zbmc.eu

This is correct (if dnsmasq isn't running) because I have a local
nameserver running at 192.168.1.2 on my LAN.

One of the two systems where dnsmasq isn't running is a very basic,
recently installed system where I have done no reconfiguration at all.
The other is my desktop machine and I *used* to have a dnsmasq running
there as a complete DHCP and DNS server but I uninstalled the dnsmasq
and just left dnsmasq-base. (I have put the dns=dnsmasq line back into
NetworkManager.conf).

I'm just wondering if the common factor is Ubuntu 12.10 and 64-bit (it
only used to work on 12.04 on my desktop system).

Looking in /var/syslog on the 64-bit system one sees:-

    Jan  6 15:39:52 test NetworkManager[900]: <info> DNS: loaded plugin dnsmasq

but that's it, nothing further at all about dnsmasq, whereas on the
32-bit system where it works there are lots of further messages from
NetworkManager about dnsmasq.


Does anyone have any ideas what might be wrong?

-- 
Chris Green