Owners of Apple's 13-inch notebooks are reporting that their Wi-Fi access is much less reliable after installing Mac OS X Leopard or more recent updates to Mac OS X Tiger, especially when the systems switch to battery power.
The exact behavior of affected systems can vary slightly, but appears to largely be connected to the computer's power supply. While the connection remains largely stable when plugged into an AC adapter, switching to battery power renders the wireless link intermittent and in many cases drops network access entirely when idle.
"Whenever I unplug my AC adapter, my wireless Internet goes a little crazy and starts continually disconnecting and reconnecting moments later," says one owner.
Users often can't detect nearby networks after restarting the card through software, but can almost always regain a dependable connection after reattaching the power plug. A handful of owners report having to restart the computer to restore the Wi-Fi connection, however.
To date, the intermittent connection issue has not been publicly acknowledged by Apple and affects systems regardless of subsequent Mac OS X updates. Both the recent 10.4.11 update and all current versions of Leopard continue to exhibit the symptoms of the problem, although some note the situation improving for their systems after the most recent upgrades to both Leopard and Tiger.
For those still affected, successful workarounds have included reverting to Mac OS X 10.4.9 when possible, and setting up commands in Terminal that send out data to keep the connection active. But since the issue does not occur when running Windows XP or Vista in Boot Camp, several users say Apple has no reason to leave the apparent flaw unresolved.
"Wi-Fi works OK under other OS X releases and also with Windows Vista running on the MacBook hardware," says one report. "Apple's engineers need to quit playing with their iPhones, roll up their sleeves and look for bugs."