Firebird error with Custom profile fields

DBMS - Firebird 2.0.5

Trying to submit the profile info in UCP after creating any custom profile field in ACP gives the error:

=====
SQL ERROR [ firebird ]

Dynamic SQL Error SQL error code = -206 Column unknown PF_STRING At line 2, column 13 [-206]

SQL

UPDATE phpbb_profile_fields_data SET pf_string = '' WHERE user_id = 2
=====

The cause for this is that Firebird converts all the names of tables and columns in queries to uppercase. If names enclosed in quotes, Firebird does not.
And the names of tables and columns in Firebird are case sensitive.
When installing the phpBB, all columns names created in upper case. But columns in the table **_profile_fields_data created when admin submits a new custom profile fields in ACP. SQL-query in includes/acp/acp_profile.php contains the column name in quotes:

=====
'ALTER TABLE ' . PROFILE_FIELDS_DATA_TABLE . " ADD \"$field_ident\" "
=====

In this case Firebird does not convert name to uppercase. But while submitting the profile info the column name in query is converted to uppercase, and, accordingly, we get an "Column unknown" error.