Error code 421 when moving/re-ordering pages in confluence 3.5.1 and SQL server

2011-04-06 14:37:19,123 ERROR [http-8081-9] [atlassian.confluence.servlet.ConfluenceServletDispatcher] sendError Could not
 execute action url: /pages/movepage.action | userName: xxxxx | referer: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
org.springframework.jdbc.UncategorizedSQLException: Hibernate operation: error performing findBySQL; uncategorized SQLException
 for SQL []; SQL state [S1000]; error code [421]; The ntext data type cannot be selected as DISTINCT because it is not 
comparable.; nested exception is java.sql.SQLException: The ntext data type cannot be selected as DISTINCT because it is not 
comparable.
Caused by: java.sql.SQLException: The ntext data type cannot be selected as DISTINCT because it is not comparable.