Malware Writers Fail to Generate Clean, Reliable Code

According to Engadget:

Microsoft is now confirming that there's a little bit of malicious code sitting at the root of [blue screen of death errors and unwanted reboots]. A rootkit, to be specific, one called Alureon that compromises the atapi.sys file and others. This rootkit makes a system call via an address that, after the update, no longer corresponds to the particular call Alureon is trying to make.