LDAP directory: error code 21 when attempting to update group with empty or whitespace description for the second time

2008-06-27 15:25:59,550 http-8095-1 ERROR [console.action.group.UpdateGroup] [LDAP: error code 21 - description: value #0 invalid per syntax]; nested exception is javax.naming.directory.InvalidAttributeValueException: [LDAP: error code 21 - description: value #0 invalid per syntax]; remaining name 'cn=a-group, o=sgi, c=us'
org.springframework.ldap.InvalidAttributeValueException: [LDAP: error code 21 - description: value #0 invalid per syntax]; nested exception is javax.naming.directory.InvalidAttributeValueException: [LDAP: error code 21 - description: value #0 invalid per syntax]; remaining name 'cn=a-group, o=sgi, c=us'
	at org.springframework.ldap.support.LdapUtils.convertLdapException(LdapUtils.java:122)
	at org.springframework.ldap.core.LdapTemplate.executeWithContext(LdapTemplate.java:786)
	at org.springframework.ldap.core.LdapTemplate.executeReadWrite(LdapTemplate.java:779)
	at org.springframework.ldap.core.LdapTemplate.modifyAttributes(LdapTemplate.java:951)
	at com.atlassian.crowd.integration.directory.connector.SpringLDAPConnector.updateGroup(SpringLDAPConnector.java:1081)
	at com.atlassian.crowd.manager.directory.DirectoryManagerGeneric.updateGroup(DirectoryManagerGeneric.java:427)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:585)