I can confirm this problem as well, with Lucid (beta 2), on a MBP (5,4), with the following from lspci:

Network controller: Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller (rev 01)

Temporary workaround (tested, verified):

1.) Run: modprobe -r wl 2.) Remove: bcmwl-kernel-source 5.60.48.36+bdcom-0ubuntu2 3.) Install: bcmwl-kernel-source_5.10.91.9+bdcom-0ubuntu4 4.) Run: modprobe wl 5.) (Optional) Stop dpkg from updating, run: echo "bcmwl-kernel-source hold" |
dpkg --set-selections

The previous version of the kernel source driver is able to find hidden access points and complete handshakes without error.

Syslog results (5.60.48.36): == Apr 10 20:16:47 ubuntu NetworkManager: <info> (eth1): supplicant connection
state: disconnected -> scanning Apr 10 20:16:57 ubuntu wpa_supplicant[1018]: CTRL-EVENT-DISCONNECTED -
Disconnect event - remove keys Apr 10 20:16:57 ubuntu NetworkManager: <info> (eth1): supplicant connection
state: scanning -> disconnected Apr 10 20:16:57 ubuntu wpa_supplicant[1018]: Authentication with
00:00:00:00:00:00 timed out. Apr 10 20:16:57 ubuntu NetworkManager: <info> (eth1): supplicant connection
state: disconnected -> scanning Apr 10 20:17:03 ubuntu NetworkManager: <info> eth1: link timed out. Apr 10 20:17:38 ubuntu NetworkManager: <info> Activation (eth1/wireless):
association took too long. ==

The above messages repeat several times, until ultimately rolling back to the previous kernel source rpm version.