I am not an expert, this topic is from my experience. I see other users who also suffer lack of wireless, so I decided to create this topic.
I had STA Broadcom proprietary driver automatically installed and working fine for months.
Recently it was broken with a log message just like http://ubuntuforums.org/showthread.php?t=1369975. It was broken without any action from me. Jockey would simply produce that error.
(A side comment: after many releases running out-of-the box with Jockey and a proprietary driver, we had the unfortunate regression that it only works for Karmic after the first update/upgrade, using wired network of course.)
I tried blacklisting this and that, I purged and reinstalled bcmwl-kernel-source, didn't work.
I tried a chip of the instructions from your famous thread to install the b43 driver and linux-backports, didn't work.
I tried madwifi following AspireOne/Ubuntu8.04 - Community Ubuntu Documentation, didn't work.
Then I had the idea of just using ndiswrapper.
I believe this should last stable until Lucid release, much more probably than any other solution subject to Ubuntu-update regressions.
1. Install ndisgtk
2. Download the Windows driver from Acer at http://global-download.acer.com/GDFi...C=Acer&SC=PA_7
3. Extract the zip file to a folder.
4. Open Windows Wireless Drivers (or run "sudo ndisgtk").
5. Click on "Install new Driver", open the folder and choose the file bcmwl5.inf (it may give an error messge, but may work anyway).
6. Check at the files inside /etc/modprobe.d that other wireless drivers are neither loaded nor blacklisted.
A comment about blacklisting:
It worked (very) well the first time, then I blacklisted everything else and rebooted. It wasn't working.
I thought that, even though it doen't make sense to me, the problem could be with the blacklisting, as it was the only thing I did between working and not-working. Bingo!
I removed the blacklistings, rebooted and it worked. Again and again.
I blacklisted again, rebooted, not working.
Removed the blacklisting, rebooted, and it was working. Rebooted again and again, and it was working.
Curious conclusion: it was working only when the other drivers were not blacklisted, even though they didn't seem to be loaded from lsmod.