I have a Compaq nc6220 with Ubuntu 11.04.
I use the machine as a ssh server to access my network from work.
So I did set Power Management to stay awake when on sector and sleep after 30
minutes when on battery. The machine is always connected on sector (unless
power failure from hydro).

But I have those messages telling me that my NIC switch in power saving state
and goes to sleep ???

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Jul 11 08:05:13 pluton NetworkManager[964]: sleep requested (sleeping: no
enabled: yes)
Jul 11 08:05:13 pluton NetworkManager[964]: sleeping or disabling...
Jul 11 08:05:13 pluton NetworkManager[964]: (eth0): now unmanaged
Jul 11 08:05:13 pluton NetworkManager[964]: (eth0): device state change:
8 -> 1 (reason 37)
Jul 11 08:05:13 pluton NetworkManager[964]: (eth0): deactivating device
(reason: 37).
Jul 11 08:05:13 pluton NetworkManager[964]: (eth0): canceled DHCP
transaction, DHCP client pid 2569
Jul 11 08:05:13 pluton NetworkManager[964]: (eth0): cleaning up...
Jul 11 08:05:13 pluton NetworkManager[964]: (eth0): taking down device.
----------------------------------------------------------

How do I set the NIC to stay awake ? I need to use my machine from work.