Comment 9 for bug 994739

Finally found the root reason of the problem! :-)

Both wl (broadcom proprietary driver) and brcmsmac (the open source driver) are installed, in 11.10 this wasn't a problem since the brcmsmac was not blacklisted, and even if the wl driver was loaded, it failed silently and brcmsmac was used instead.

In 12.04, the wl driver has been updated to version 5.100.82.38+bdcom-0ubuntu6.1 which includes the following fix:

https://bugs.launchpad.net/ubuntu/+source/bcmwl/+bug/873117/comments/36

that basically blacklists the brcmsmac module, forcing the wl proprietary driver to be in use.

When the wl driver is in use, resume takes 30 seconds to associate to the network, but when the brcmsmac driver is in use, it just takes 5 seconds.

I just blacklisted the 'wl' module, and happily using the brcmsmac now in 12.04, without any issues. Problem solved!