Thank you for feedback and your testing effort.
I contacted InterBase R&D. Probably they will 
be able to explain this issue.


-- 
With best regards,
Dmitry Arefiev / FireDAC Architect
FireDAC - Firebird, SQLite, MySQL, SQL Server, Oracle, PostgreSQL, 
DB2, SQL Anywhere, Access, Informix, ODBC high-speed data access lib