I found quick matches with in both SunSolve and Google.... Sunsolve:
"PBR Sig" stands for Partition Boot Record Signature. Plus
pretty similar conclusion to the Google page below.
Google:
http://asupergeek.blogspot.com/2007/06/bad-pbr-sig.html
Richard Wright wrote, On 01/05/09 00:27:
> The last time I got a Bad PBR sig message it was from a IDE hard drive and it
> turned out to be a faulty motherboard. It's an annoying message though as it
> doesn't seem to be very well documented anywhere.
>
