Index: src/main/java/com/xpn/xwiki/tool/backup/Importer.java
===================================================================
--- src/main/java/com/xpn/xwiki/tool/backup/Importer.java	(revision 3924)
+++ src/main/java/com/xpn/xwiki/tool/backup/Importer.java	(working copy)
@@ -31,6 +31,8 @@
 import java.io.IOException;
 
 import org.hibernate.Session;
+import org.hibernate.dialect.Dialect;
+import org.hibernate.dialect.HSQLDialect;
 
 /**
  * Import a set of XWiki documents into an existing database.
@@ -99,6 +101,10 @@
 
         if (XWikiHibernateStore.class.isAssignableFrom(store.getClass())) {
             XWikiHibernateStore hibernateStore = (XWikiHibernateStore) store;
+            
+            // check that is HSQLDB
+            Dialect dialect = Dialect.getDialect(hibernateStore.getConfiguration().getProperties());
+            if (!(dialect instanceof HSQLDialect)) return;
 
             boolean bTransaction = true;
             try {