If a squeezebox2, configured to get IP by DHCP is power cycled, it no longer
renews its DHCP lease, but continues to use the DHCP-assigned address anyway.

Note: by power cycle, I mean physically remove the power plug and then re-insert it.

When power comes back, if the "press right to configure networking" prompt is
allowed to time-out, the SB resumes it's previous network settings, including
the IP address. However during boot it doesn't interact at all with the DHCP
server or even probe  the address using an ICMP echo request, and it never again
sends a DHCPREQUEST to renew the DHCP lease.

This means that the DHCP lease will eventually time-out at the server; either
during the time the SB is down, or later when it has come back up but is no
longer sending renewal requests. The DHCP server will mark the address as free
and available for re-allocation but the SB will still be using it, leading to
the possibility of an address conflict.

Under these circumstances (previous DHCP lease, reboot) I would expect the DHCP
client to come up in INIT-REBOOT state, and start by sending a DHCPREQUEST to
attempt to claim the old lease. If that fails then the whole DHCPDISCOVER,
DHCPOFFER process would start ne novo.

I've rated this a major bug since it can lead to use of an IP address after the
DHCP lease has expires: this breaks the promise that a DHCP client makes when
taking a lease, that use of the address will cease before the lease expires,
unless the lease is renewed.