I'm using a wireless network at home, and a wired network at the
office. When I move from home to the office in the morning, I suspend
my machine (by pressing Fn+Suspend on my x300). when I arrive at
the office I connect the cable, and opens the lid, and the machine
resumes. The machine wakes up and detects that it has a cabled connection,
and connects. But the problem is that resolv.conf still holds the entry
for my home connection, so I need to run "sudo resolvconf -d eth2"
before things start to work properly. When I get home in the evening,
the same thing happens, except now I need to run "sudo resolvconf -f eth0"
to remove then cabled connection.

Not sure if it's fixed, in testing/unstable version, as this will include
a lot more upgrades than I want to do at the moment :(

If you think it's fixed, I could try to backport, and check.

Another aspect of this bug: if there is just one interface,
NetworkManager fails to run "resolvconf -d NetworkManager"
when it deconfigures that interface.  (Tried with 0.8.1-6+squeeze1.)

It seems that NM maintains a list of nameservers and sometimes
sends these to resolvconf using "resolvconf -a NetworkManager",
and that's it.

To play nicely with resolvconf, NM should run

    resolvconf -a ${IFACE}.NetworkManager

for each separate interface $IFACE, and should run

    resolvconf -d ${IFACE}.NetworkManager

when $IFACE is deconfigured.  The value of IFACE should
follow established standards for interface naming.  If this is
done then resolvconf will order the nameserver list according
to interface-order(5).