Not sure if this will help with this, but sometimes it helps to reset the PRAM. Try this when booting:
Sometimes there might be some old entries somewhere.
Another one is the http://guides.macrumors.com/Resetting_The_NVRAM but I think the PRAM should be good enough. I had to do this once but I forgot why. I think it was blootooth related but this might affect hardware related errors. So, probably worth a try.
So, after the new announcement of FUSION drive, I am wondering if it might make sense (and if it is possible) to create your own FUSION drive setup on an older machine like my MBP. Since we talked about replacing the original HDD with a SSD and swapping the optical drive for the HDD, it seems we may have the hardware components of a FUSION drive available right there.
Now, if OS X ML comes with this special edition of disk utility that supports FUSION drive, the question is, if we can stitch this together in a way that you have a nice real fusion drive there. It seems having an extra partition on the hard drive for Bootcamp shall be OK, but it seems you cannot partition the flash drive. I could live with this. But instead of having two seperate drives it would be very cool to "fuse" them together to one fusion drive and have ML move the software according to what's used the most.
Let's see if anyone can get this to work or finds a blog entry for making this happen... Any thoughts?