Why is the iTunes Match setup process causing iTunes (and my machine) to freeze?

I purchased iTunes Match several days ago, and it continues to freeze iTunes, subsequently locking up my machine. It keeps getting stuck on step 1 of the setup process (analyzing my library); I have left it overnight several times with no luck.

At this point, I really just want my $25 back, but has anyone else encountered this problem? Is there a workaround?