[Zope] problem with ZODB

Hello Everyone.. I have been a silent member of the list mostly.. There is a slight problem that needs to be addressed rather urgently... The thing is that though unicode strings can be input and retrieved into the database through Zope.. For example, for the table EMPLOYEE<emp_id, first_name, last_name, salary> the query select * from EMPLOYEE where emp_id = 3 (some number) works but select * from EMPLOYEE where first_name= 'some unicode string' doesn't work... I'd appreciate some input on this.. --JV.