techtool states it finds bad blocks on my mac mini (feb 2009) and that i need to wipe the drive? I've been getting bad blocks found ever since I bought this computer. And I am lead to believe that a wipe won't keep more bad blocks from forming. Backing up and wiping isn't difficult - having to reload every piece of software and hardware and file is a huge inconvenience and halts up production time. 1- is what i have read about bad blocks true? 2- how do i keep them from forming so I won't have to have downtime everytime a bad block appears?