I am seeing this error message in the error log
42704: TABLE in USERNAME type *FILE not found. SQLCODE=-204
This error message was not produced before this week. I think it has something to do with the IBM system and not with the PHP/SQL code. I spent all day yesterday trying to figure it out but have no idea still. I am pretty sure the library that has the TABLE in it is in the users profile on the system so I don't understand why it says it can't find it.
It is a library list or current library issue. See this related question and answer for more information that may be helpful: Odbc connection string format, not finding files