wsad下使用log4j出现奇怪问题，求助。

我的配置步骤是：
1.建立类路径LOG4j，引用C:/Program Files/IBM/WebSphere Studio/Application Developer/v5.1/wstools/eclipse/plugins/org.apache.axis_1.0/lib/ log4j-1.2.4.jar
2.在属性->构建路径->lib->添加变量,将刚才的LOG4j加入。
3.在javasource下面添加并配置log4j.properties，具体内容就不细说了，估计错误不在这里。
4.在我需要使用的类中添加代码：
...
import org.apache.log4j.*;
public class ListAccountsAction extends Action {
Logger logger =Logger.getLogger(ListAccountsAction.class.getName());
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws Exception {
。。。
logger.error("execute方法有错误发生");
。。。
}
运行时老是提示：
[06-9-4 10:10:58:594 CST] 4d4140db SystemErr R log4j:ERROR Could not instantiate class [com.syit.core.com.log.SyeapLogLayout].
[06-9-4 10:10:58:594 CST] 4d4140db SystemErr R java.lang.ClassNotFoundException: com.syit.core.com.log.SyeapLogLayout
...
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.Logger.getLogger(Logger.java:85)
...
这个com.syit.core.com.log.SyeapLogLayout是在我的机器上另一个jar包syeap-common.jar中，我的工程里根本就没有使用它，是风马牛不相及的，怎么报这个错误，我百思不得其解，希望知道答案的不息赐教，谢谢。

更详细一点的错误信息如下：
[06-9-4 10:10:58:594 CST] 4d4140db SystemErr R log4j:ERROR Could not instantiate class [com.syit.core.com.log.SyeapLogLayout].
[06-9-4 10:10:58:594 CST] 4d4140db SystemErr R java.lang.ClassNotFoundException: com.syit.core.com.log.SyeapLogLayout
[06-9-4 10:10:58:594 CST] 4d4140db SystemErr R at com.ibm.ws.classloader.CompoundClassLoader.findClass(CompoundClassLoader.java(Compiled Code))
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java(Compiled Code))
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at java.lang.ClassLoader.loadClass(ClassLoader.java(Compiled Code))
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at java.lang.Class.forName1(Native Method)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at java.lang.Class.forName(Class.java(Compiled Code))
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.helpers.Loader.loadClass(Loader.java:158)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.helpers.OptionConverter.instantiateByClassName(OptionConverter.java:309)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.helpers.OptionConverter.instantiateByKey(OptionConverter.java:112)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:632)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:603)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyConfigurator.java:500)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:406)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:432)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:456)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at at org.apache.log4j.LogManager.<clinit>(LogManager.java:145).null(Unknown Source)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at org.apache.log4j.Logger.getLogger(Logger.java:85)
[06-9-4 10:10:58:609 CST] 4d4140db SystemErr R at itso.strutsweb.actions.ListAccountsAction.<init>(ListAccountsAction.java:45)