Juan Cabanela’ s fix for the Wallstreet ‘Fan on during Sleep’ Bug in Mac OS X was updated with this notice. ” WARNING: If you downloaded the extension before 4pm EST February 28, 2002, the file was likely corrupted. Reload it.”

Ever since MacOS X came out, there has been a very annoying bug for Wallstreet PowerBook users. If you place the Wallstreet to sleep, and then unplug it, the fan in the PowerBook comes on and will not turn off. This rapidly drains the battery, somewhat eliminating the benefit of placing the system to sleep.

Thankfully, it turns out the bug can be traced to code in the open source part of MacOS X… Darwin. I found a fix for the Wallstreet sleep bug by digging around Apple’s Darwin Open Source website. In a nutshell, the problem lies in the AppleHeathrow.kext extension in the /System/Library/Extensions directory. Patching this extension to turn of a particular chip during sleep seems to fix the problem.