Error using CLOB field

I'm using a CLOB field in IDS 9.4 with JDBC driver 3.00.JC3. My data access layer consists of Hibernate 3/EJB3. Whenever I access a CLOB field, I get the following error ... Caused by: java.sql.SQLException: Can't convert tonull at com.informix.util.IfxErrMsg.getSQLMinorException(IfxErrMsg.java:536) at com.informix.jdbc.IfxObject.toCharacterStream(IfxObject.java:633) at com.informix.jdbc.IfxResultSet.getCharacterStream(IfxResultSet.java:893) at com.informix.jdbc.IfxResultSet.getCharacterStream(IfxResultSet.java:916) at org.jboss.resource.adapter.jdbc.WrappedResultSet.getCharacterStream(WrappedResul tSet.java:482) at org.hibernate.type.StringClobType.nullSafeGet(StringClobType.java:39) at org.hibernate.type.CustomType.nullSafeGet(CustomType.java:104) at org.hibernate.type.AbstractType.hydrate(AbstractType.java:81) at org.hibernate.persister.entity.AbstractEntityPersister.hydrate(AbstractEntityPer sister.java:1983) at org.hibernate.loader.Loader.loadFromResultSet(Loader.java:1372) at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1300) at org.hibernate.loader.Loader.getRow(Loader.java:1197) at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:569) at org.hibernate.loader.Loader.doQuery(Loader.java:689) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:2 24) at org.hibernate.loader.Loader.doList(Loader.java:2145) Writes on the other hand always work and using a TEXT field is no problem for reads or writes. Any ideas? Thanks