After installing 10.5.8, my Wi-Fi when my computer is unplugged no long works. When the computer is plugged in however the internet works perfectly but the second I unplug the power cord, the internet cuts off. Has anyone else experienced this after updating to 10.5.8 and solved the problem. I have a 2.4GHz Penryn MacBook Pro. Also, could someone give me a link to instructions on downgrading the firmware back to 10.5.7. Thanks.