existentia

Like many people, I recently downloaded and installed the Mac OS 10.4.10 update via Software Update onto my Apple MacBook. All appeared to be well except for one apparent bug this update has introduced into the system. Many other users are reporting this same problem but Apple have yet to address this issue (it appears to have got fixed is Mac OS 10.5). In the hope of helping a few other people out with this I will detail the problems I’ve experienced and what I’ve done to workaround them.

First of all, I would only ever see this problem in the following scenario:

• My MacBook is running on battery (i.e. it’s not plugged into the mains)
• My MacBook is connected to my home wireless network that is encrypted using either WPA+WPA2 mixed mode or just WPA2. My Belkin N1 Wireless Modem Router offers me both these options as well as the older WEP encryption modes.

The problems I experienced were the same most other people have been reporting. Frequently (every 10 - 15 minutes or so) my wireless connection would just drop. Sometimes Mac OS thought it was still connected to the wireless network even though I couldn’t access any web sites etc. Switching the Airport card off and then back on again from within Mac OS appeared to the resolve the issue, albeit temporary. What was troubling and much more irritating is that after a few of these drop-outs Mac OS would kernel panic (i.e. hang completely). Following the required reboot the crash report would always point the finger at the Airport wireless card driver (com.apple.driver.AirPort.Atheros).

From what I can work out this problem seems to be with the updated driver used by the Airport card (that must be installed by the Mac OS 10.4.10 update) and how it handles specifically configured WPA and WPA2 encrypted wireless networks. The fact this problem does not appear to manifest itself when the MacBook is plugged into the mains also suggests that power throttling on the wireless card (if indeed it does that - anyone?) might have something to do with this as well. Whatever the root cause is, Apple have yet to fix it.

So how did I workaround this problem?

I did two things. I first configured my wireless network to use only WPA encryption using TKIP (not AES). I then deleted the wireless network locations configured on my MacBook through Network and then used the Airport Assistant to detect and connect to my re-configured wireless network. Since then, all has been well!

It’s not ideal as ideally I’d like my wireless network using WPA2 with AES for maximum security as it was before. But until Apple fix this problem then I don’t really have a choice unless I keep my MacBook plugged into the mains! And that really doesn’t make much sense for a laptop…