Here is an unofficial "errata", mostly stylistic issues should you get a copy:

http://www.cs.northwestern.edu/academics/courses/325/reading...

ANSI CL was the first book that helped me enjoy Lisp. My previous books were all vintage "AI" books that were dull. However, one quickly grows out the Graham subset of Common Lisp and ends up using the language to its full potential (i.e. with proper iteration, condition system, object system, exceptions, packages and modules.)