Index: src/main/java/net/sf/maventaglib/ValidateRenderer.java
===================================================================
--- src/main/java/net/sf/maventaglib/ValidateRenderer.java	(Revision 200)
+++ src/main/java/net/sf/maventaglib/ValidateRenderer.java	(Arbeitskopie)
@@ -77,10 +77,16 @@
     private Class tagExtraInfoClass;
 
     /**
-     * javax.servlet.jsp.tagext.SimpleTag class loaded using the project classloader.
+     * javax.servlet.jsp.tagext.SimpleTag class loaded using the project classloader.  
      */
     private Class simpleTagClass;
+    
+    /**
+     * the expected JSP version  
+     */
+    private int expectingTagsFromJspVersion;
 
+    
     /**
      * @param sink
      */
@@ -91,9 +97,15 @@
         this.tlds = tlds;
         this.log = log;
         this.projectClassLoader = projectClassLoader;
+        
+        // Expect at least the tags from JSP 1.x. Should be a config setting. 
+        // If we know the JSP version before we try to get the support classes,
+        // we could provide a better error handling ("missing libraries") 
+        this.expectingTagsFromJspVersion = 1;
 
         try
         {
+            // JSP >= 1
             tagSupportClass = Class.forName( "javax.servlet.jsp.tagext.TagSupport", true, this.projectClassLoader ); //$NON-NLS-1$
         }
         catch ( ClassNotFoundException e )
@@ -102,6 +114,7 @@
         }
         try
         {
+            // JSP >= 1
             tagExtraInfoClass = Class.forName( "javax.servlet.jsp.tagext.TagExtraInfo", true, this.projectClassLoader ); //$NON-NLS-1$
         }
         catch ( ClassNotFoundException e )
@@ -110,11 +123,18 @@
         }
         try
         {
+            // JSP >= 2
             simpleTagClass = Class.forName( "javax.servlet.jsp.tagext.SimpleTag", true, this.projectClassLoader ); //$NON-NLS-1$
+
+            // If the SimpleTagClass has been found, then expect Tags from JSP 2 
+            // If the SimpleTagClass hass not been found, then it is not necessarily an error.
+            // Either the project uses an earlier of the JSP spec and makes no use of SimpleTag at all anyways.
+            // Or the classes are missing, which will throw an exception later anyways. 
+            expectingTagsFromJspVersion = 2;
         }
         catch ( ClassNotFoundException e )
         {
-            log.error( Messages.getString( "Validate.error.unabletoload.SimpleTag" ) ); //$NON-NLS-1$
+            //log.error( Messages.getString( "Validate.error.unabletoload.SimpleTag" ) ); //$NON-NLS-1$
         }
 
     }
@@ -223,12 +243,16 @@
         {
             Class tagClass = Class.forName( className, true, this.projectClassLoader );
 
-            if ( tagSupportClass == null
-                || ( !tagSupportClass.isAssignableFrom( tagClass ) && !simpleTagClass.isAssignableFrom( tagClass ) ) )
+            if (expectingTagsFromJspVersion < 2) 
             {
-                extend = false;
+                // extend only true, if tagClass derives from TagSupport
+                extend = tagSupportClass.isAssignableFrom( tagClass );
+            } else if (expectingTagsFromJspVersion >= 2) 
+            {
+                // extend only true, if tagClass derives from TagSupport or derives from SimpleTag
+                extend = tagSupportClass.isAssignableFrom( tagClass ) || simpleTagClass.isAssignableFrom( tagClass ); 
             }
-
+            
             try
             {
                 tagObject = tagClass.newInstance();
@@ -402,7 +426,7 @@
             if ( tldType != null && tagType != null )
             {
                 Class tldTypeClass = getClassFromName( tldType );
-
+                
                 if ( !tagType.isAssignableFrom( tldTypeClass ) )
                 {