I get tons of messages like the following which makes it extremely hard to read the .log file of Eclipse. The issue is already reported at https://issues.jboss.org/browse/JBIDE-14555. Perhaps comeone from the JBoss Tools team has some time to look into this issue.
!ENTRY org.jboss.tools.arquillian.core 4 0 2013-05-25 08:10:34.570
!MESSAGE Could not initialize class de.shop.util.ArchiveBuilder