This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
You could be missing the aopalliance-1.0.jar file. I don't believe this is directly part of the distribution (at least it wasn't for spring-framework-3.0.0.RELEASE). I've since been building with the STS and the Spring Template Project, which builds out a Maven-based project with all the basic dependencies pre-set in the pom.xml file.