Error Message -47 = Huh?

Question

OK, so why after I spend hours and hours on my two and only big projects in GB, and get it perfect, does it not allow me to:
either Share>Export Song to iTunes
or
Export Song to Disk
It happened twice now on different projects. Oh and Two's the count. Not pleased.
Both had imported an audio clip plus: one used midi, and the other a mic to add data to the filesize.
These are only 3 minute songs, so it shouldn't be too huge a file.
Good thing I could Audio Hijack it or I would have lost both.
"-47" means what, other than the traditional explative?
And where's the downloadable list of error messages? I looked but couldn't find much that appeared on point.
Thanks.

Answer 1

Thanks to all three who responded. I got it solved based on the three posts, and it may help everybody who has had this (common) problem.
istevius suggested it might be an IO problem and that it might be looking for an external (addressing?).
Scary Larry reported a re-install solved the problem.
xs4is said that a re-install was a last choice.
This reminded me of a topic I once posted about having problems with auto-updating iLife. And the conversation there was very similar to this one.
I was told to repair permissions, and that OnyX was a downloadable program from
http://www.versiontracker.com/macosx/
Well, just now, upon repairing permissions, the problem is solved!
I never thought to do it because I had just repaired them a couple (3-4?) days ago.
Looks like I'll have OnyX run a timed maintenance every day as iLife seems to get out of kilter constantly.
Thanks all. Looks like we have our organic neural net working.