If I run these two queries seperately, they find 
more records than if I "orExp" together the qualifiers.

Tested on SQL server & MS Access, same result.
=================================================

	// This Java code will result in the SQL query immediately below...
	SelectQuery query1=new SelectQuery(ElcRole.class);
	query1.setQualifier(ExpressionFactory.matchExp(ElcRole.ELC_ROLEMEMBER_ARRAY_PROPERTY + "." + ElcRolemember.TO_SYS_USER_PROPERTY, getSysUser()));
	List l=context.performQuery(query1);
	return l;

SELECT DISTINCT t0.ELCROLE_NAME, t0.ELCROLE_ID, t0.SYSUSER_ID FROM ELC_ROLE t0, ELC_ROLEMEMBER t1 WHERE t0.ELCROLE_ID = t1.ELCROLE_ID AND (t1.SYSUSER_ID = 'BD93F348-8C02-4742-BA97-2456E5CD3881') 
 
ELCROLE_NAME					ELCROLE_ID								SYSUSER_ID
Prosesseier						E7BE040B-F0E3-4ecf-88A6-4B81BF7AE865	
Saksbehandler HMS				0636F7A4-006B-4926-873F-B5CF888F239C	
Saksbehandler Innkjøp			E5DED96B-5F93-4575-85A4-1C14D94B9744	
Saksbehandler Lager				48461B6C-791B-11d4-8792-00508BCE14E0	FF3C97BB-8899-444c-8C6E-91E64D087E86
 
 
	// This Java code will result in the SQL query immediately below...
	SelectQuery query1=new SelectQuery(ElcRole.class);
	query1.setQualifier(ExpressionFactory.matchExp(ElcRole.TO_SYS_USER_PROPERTY, getSysUser()));
	List l=context.performQuery(query1);
	return l;
		
SELECT t0.ELCROLE_NAME, t0.ELCROLE_ID, t0.SYSUSER_ID FROM ELC_ROLE t0 WHERE t0.SYSUSER_ID = 'BD93F348-8C02-4742-BA97-2456E5CD3881'

ELCROLE_NAME					ELCROLE_ID								SYSUSER_ID
Saksbehandler Drift/Vedlikehold	04190624-7503-11d4-9078-00508BD89D95	BD93F348-8C02-4742-BA97-2456E5CD3881
Saksbehandler Produksjon		04190625-7503-11d4-9078-00508BD89D95	BD93F348-8C02-4742-BA97-2456E5CD3881
Testrolle 4						07AF23BD-7DCA-41cc-9268-A4A08CF0B2DF	BD93F348-8C02-4742-BA97-2456E5CD3881
Testrolle 2						A5E8553F-BB4D-4158-BA53-D8F206817938	BD93F348-8C02-4742-BA97-2456E5CD3881
Saksbehandler Forespørsel		A5F7E0D8-E204-478f-A7A4-DCC07C712673	BD93F348-8C02-4742-BA97-2456E5CD3881
Testrolle 1						AEBEDF2E-2656-4733-99A7-2EAC231DE379	BD93F348-8C02-4742-BA97-2456E5CD3881
Testrolle 3						B90B4CCB-43EA-4187-B139-4138041A2F8D	BD93F348-8C02-4742-BA97-2456E5CD3881
Saksbehandler Transport			E17775E2-897A-41d3-8CC0-D96E24E15DE7	BD93F348-8C02-4742-BA97-2456E5CD3881
 
 
Does not find "Testrolle 4"
===========================

	// This Java code will result in the SQL query immediately below...
	SelectQuery query1=new SelectQuery(ElcRole.class);
	query1.setQualifier(ExpressionFactory.matchExp(ElcRole.ELC_ROLEMEMBER_ARRAY_PROPERTY + "." + ElcRolemember.TO_SYS_USER_PROPERTY, getSysUser()).
			orExp(ExpressionFactory.matchExp(ElcRole.TO_SYS_USER_PROPERTY, getSysUser())));
	List l=context.performQuery(query1);
 
SELECT DISTINCT t0.ELCROLE_NAME, t0.ELCROLE_ID, t0.SYSUSER_ID FROM ELC_ROLE t0, ELC_ROLEMEMBER t1 WHERE t0.ELCROLE_ID = t1.ELCROLE_ID AND ((t1.SYSUSER_ID = 'BD93F348-8C02-4742-BA97-2456E5CD3881') OR (t0.SYSUSER_ID = 'BD93F348-8C02-4742-BA97-2456E5CD3881'))

ELCROLE_NAME				ELCROLE_ID								SYSUSER_ID
Prosesseier					E7BE040B-F0E3-4ecf-88A6-4B81BF7AE865	
Saksbehandler Forespørsel	A5F7E0D8-E204-478f-A7A4-DCC07C712673	BD93F348-8C02-4742-BA97-2456E5CD3881
Saksbehandler HMS			0636F7A4-006B-4926-873F-B5CF888F239C	
Saksbehandler Innkjøp		E5DED96B-5F93-4575-85A4-1C14D94B9744	
Saksbehandler Lager			48461B6C-791B-11d4-8792-00508BCE14E0	FF3C97BB-8899-444c-8C6E-91E64D087E86
Saksbehandler Produksjon	04190625-7503-11d4-9078-00508BD89D95	BD93F348-8C02-4742-BA97-2456E5CD3881
Saksbehandler Transport		E17775E2-897A-41d3-8CC0-D96E24E15DE7	BD93F348-8C02-4742-BA97-2456E5CD3881


Hmmm.... I think the SQL should have been a LEFT OUTER JOIN, but Cayenne does not support
OUTER JOINs. Is OUTER JOIN a red herring here?

SELECT DISTINCT t0.ELCROLE_NAME, t0.ELCROLE_ID, t0.SYSUSER_ID
FROM         ELC_ROLE t0 LEFT OUTER JOIN
                      ELC_ROLEMEMBER t1 ON t0.ELCROLE_ID = t1.ELCROLE_ID
WHERE     (t1.SYSUSER_ID = 'BD93F348-8C02-4742-BA97-2456E5CD3881') OR
                      (t0.SYSUSER_ID = 'BD93F348-8C02-4742-BA97-2456E5CD3881')
                      
=>

Prosesseier	E7BE040B-F0E3-4ecf-88A6-4B81BF7AE865	
Saksbehandler Drift/Vedlikehold	04190624-7503-11d4-9078-00508BD89D95	BD93F348-8C02-4742-BA97-2456E5CD3881
Saksbehandler Forespørsel	A5F7E0D8-E204-478f-A7A4-DCC07C712673	BD93F348-8C02-4742-BA97-2456E5CD3881
Saksbehandler HMS	0636F7A4-006B-4926-873F-B5CF888F239C	
Saksbehandler Innkjøp	E5DED96B-5F93-4575-85A4-1C14D94B9744	
Saksbehandler Lager	48461B6C-791B-11d4-8792-00508BCE14E0	FF3C97BB-8899-444c-8C6E-91E64D087E86
Saksbehandler Produksjon	04190625-7503-11d4-9078-00508BD89D95	BD93F348-8C02-4742-BA97-2456E5CD3881
Saksbehandler Transport	E17775E2-897A-41d3-8CC0-D96E24E15DE7	BD93F348-8C02-4742-BA97-2456E5CD3881
Testrolle 1		AEBEDF2E-2656-4733-99A7-2EAC231DE379	BD93F348-8C02-4742-BA97-2456E5CD3881
Testrolle 2		A5E8553F-BB4D-4158-BA53-D8F206817938	BD93F348-8C02-4742-BA97-2456E5CD3881
Testrolle 3	B90B4CCB-43EA-4187-B139-4138041A2F8D	BD93F348-8C02-4742-BA97-2456E5CD3881
Testrolle 4	07AF23BD-7DCA-41cc-9268-A4A08CF0B2DF	BD93F348-8C02-4742-BA97-2456E5CD3881