Running 11.10 on a Lenovo B570, maybe a month old. When I try to connect to a network, wired or wireless,
nm-applet does its normal "connecting" animation, but sort of "spasming" at the end of the loop. I think what appears in that icon's place for a frame or so might be a "loading applet" icon. After maybe a minute, the applet gives up trying to connect. This behavior started in the past several hours and has persisted after a reboot.
This output may be relevant:
$ netstat -nr Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface
7 March 2012
This has now resurfaced. In hopes of providing further useful information:
$ cat /etc/network/interfaces auto lo iface lo inet loopback