Wow, a strange one there. The only thing I can think of is that you may be are doing this inside a directory where you haven't got write permissions or something. Try to do the same as super user (type "su", enter root password, then try to reconfigure).
You could also try to reinstall GCC. But don't attempt to do that unless you've tried everything else. I can tell you from my experience that this procedure can get really nasty (last time I uninstalled gcc libs, I had to reinstall whole OS, so...
)
By the way, what distro are you using?
