Not enough space on the disk
I’m having the exact same problem except that BookSmart is taking every bit of available space, 134 GB (you read that right), on the boot drive of my Mac. I am running OS 10.4.11 and I know the stated minimum OS requirement for BookSmart is OS 10.5 and up but when I try to run an updater on my system, a brand new Mac Pro, the file from Apple won’t run. I don’t know what this is about but I will also add that the BookSmart software has crashed a couple of times, once taking my system down with it. I believe the problems lie with the BookSmart software and not my system which is robust and has not had these problems before.