help!!运行lumaqq出错

fluentlife

出错信息如下:
Exception in thread "main" java.lang.NoClassDefFoundError: while resolving class: edu.tsinghua.lumaqq.LumaQQ
   at java.lang.VMClassLoader.transformException(java.lang.Class, java.lang.Throwable) (/usr/lib64/libgcj.so.6.0.0)
   at java.lang.VMClassLoader.resolveClass(java.lang.Class) (/usr/lib64/libgcj.so.6.0.0)
   at java.lang.Class.initializeClass() (/usr/lib64/libgcj.so.6.0.0)
   at java.lang.Class.forName(java.lang.String, boolean, java.lang.ClassLoader) (/usr/lib64/libgcj.so.6.0.0)
   at gnu.java.lang.MainThread.run() (/usr/lib64/libgcj.so.6.0.0)
Caused by: java.lang.ClassNotFoundException: java.lang.StringBuilder not found in gnu.gcj.runtime.SystemClassLoader{urls=[file:/root/LumaQQ/lib/xerces.jar,file:./,file:/root/LumaQQ/lib/swt.jar,file:/root/LumaQQ/lib/poifs.jar,file:./,file:/root/LumaQQ/lib/org.eclipse.ui.workbench_3.1.0.jar,file:/root/LumaQQ/lib/org.eclipse.osgi_3.1.0.jar,file:./,file:/root/LumaQQ/lib/org.eclipse.jface_3.1.0.jar,file:/root/LumaQQ/lib/org.eclipse.core.runtime_3.1.0.jar,file:./,file:/root/LumaQQ/lib/lumaqq.jar,file:/root/LumaQQ/lib/log4j-1.2.8.jar,file:./,file:/root/LumaQQ/lib/jql-20050817231959.jar,file:/root/LumaQQ/lib/jdom.jar,file:./,file:/root/LumaQQ/lib/commons-logging.jar,file:/root/LumaQQ/lib/commons-codec-1.3.jar,file:./], parent=gnu.gcj.runtime.ExtensionClassLoader{urls=[], parent=null}}
   at java.net.URLClassLoader.findClass(java.lang.String) (/usr/lib64/libgcj.so.6.0.0)
   at java.lang.ClassLoader.loadClass(java.lang.String, boolean) (/usr/lib64/libgcj.so.6.0.0)
   at java.lang.ClassLoader.loadClass(java.lang.String) (/usr/lib64/libgcj.so.6.0.0)
   at java.lang.Class.forName(java.lang.String, boolean, java.lang.ClassLoader) (/usr/lib64/libgcj.so.6.0.0)
   ...4 more

是不是我下的jre版本和我的系统冲突?系统是FC4-x86-64的.
请问怎么做?