I had installed the IFS driver to read my Unbuntu partition in Vista so I could grab a few files off of it. It didn't close the filesystem properly and I got dumpped to a root prompt on the next boot with a message to run fsck manually. The best part was one of the other errors that showed up when all this happened.
"apt-get is not installed. To install apt-get type 'apt-get install apt' "
I just wanted to share.