I recently installed Ubuntu 6.06 on my Acer 5672 and everything worked flawlessly. I realized that the 386 kernel was not going to utilize my second core, so I switched to the 686 kernel. Now my wireless does not work. If I switch to the 386 at boot, wireless works fine - 1 CPU core - if I go to 686, no wireless, both cores.

Any ideas?

The wireless chipset is 3945ABG.

Thanks

Interesting... sounds like a conflict of somekind...
I recently loaded Ubuntu 6.06 onto my friends HP Pavillion Dual Core which has the same wireless lan as your machine...
I did not try the 686 sets so i did not have both cores working however i did notice that when the machine first boots (just before the splash screen loads) ... It complains about PCI Interupt problems... It then boots up fine and the wireless works..

I wonder if this could in someway relate ? Unsure but just thought i would give my 2 cents

* in a terminal what happens if you type $sudo iwconfig ? is the wireless device listed in there?
if it is NOT marked as having wireless extensions.. then try:
$lsmod
you should notice that the IPW3945 module is loaded and also ieee80211 ... You may also have a firmware class listing that is associated with the IPW stuff....

If you find the IPW modules ARE loaded but in $iwconfig the device is NOT listed then check and make sure the IPW firmware is installed in /lib/firmware/kernel version

there should be a bunch of filename.fw listings in there...