Weired exceptions

Tonight I wanted to work on the new wizard page for TestNG support.
After integrating a first version some weired errors occured:

04.11.08 20:25:57 [0x0-0x2a02a].org.eclipse.eclipse[216] java.lang.NoClassDefFoundError: ch/ethz/iks/slp/ServiceLocationEnumeration
04.11.08 20:25:57 [0x0-0x2a02a].org.eclipse.eclipse[216] at java.lang.Class.getDeclaredConstructors0(Native Method)
04.11.08 20:25:57 [0x0-0x2a02a].org.eclipse.eclipse[216] at java.lang.Class.privateGetDeclaredConstructors(Class.java:2357)
04.11.08 20:25:57 [0x0-0x2a02a].org.eclipse.eclipse[216] at java.lang.Class.getConstructor0(Class.java:2671)
04.11.08 20:25:57 [0x0-0x2a02a].org.eclipse.eclipse[216] at java.lang.Class.newInstance0(Class.java:321)
04.11.08 20:25:57 [0x0-0x2a02a].org.eclipse.eclipse[216] at java.lang.Class.newInstance(Class.java:303)
04.11.08 20:25:57 [0x0-0x2a02a].org.eclipse.eclipse[216] at org.eclipse.osgi.frame