Index: C:/home/azusa/docs/chura/s2dao-1.0.x/s2-dao/src/main/java/org/seasar/dao/impl/UpdateModifiedOnlyCommand.java
===================================================================
--- C:/home/azusa/docs/chura/s2dao-1.0.x/s2-dao/src/main/java/org/seasar/dao/impl/UpdateModifiedOnlyCommand.java	(revision 922)
+++ C:/home/azusa/docs/chura/s2dao-1.0.x/s2-dao/src/main/java/org/seasar/dao/impl/UpdateModifiedOnlyCommand.java	(working copy)
@@ -26,6 +26,7 @@
 import org.seasar.extension.jdbc.PropertyType;
 import org.seasar.extension.jdbc.StatementFactory;
 import org.seasar.framework.log.Logger;
+import org.seasar.framework.util.StringUtil;
 
 /**
  * @author manhole
@@ -81,8 +82,8 @@
             final String keyName = bmd.getPrimaryKey(i);
             sb.append(keyName);
             sb.append("=");
-            sb.append(bmd.getPropertyType(keyName).getPropertyDesc().getValue(
-                    bean));
+            sb.append(bmd.getPropertyType(StringUtil.replace(keyName, "_", ""))
+                    .getPropertyDesc().getValue(bean));
             if (i == size - 1) {
                 sb.append("}");
             }