prepared statement using char/varchar type with ODBC and Inform ix doesn't work

A Qt console client application (running on Windows XP) executed a prepared SQL SELECT statement using Qt ODBC Driver and IBM Informix Client SDK 2.90 TC4 (contains IBM INFORMIX ODBC DRIVER 2.90.00.12497). The statement runs against Informix DB server (IDS 11.10 FC2 running on Solaris SunOS 5.10 sun4v sparc). SQL SELECT statement contains a parameterised where clause for a character column.

When using Qt 4.1.4 the prepared statement was executed without error. When using Qt 4.3.4 however, the following QSqlError occurred:

QODBCResult::exec: Unable to execute statement:
[Informix][Informix ODBC Driver][Informix]Illegal attempt to convert Text/Byte blob type.

error type : 2
error number : -608
error DB msg : [Informix][Informix ODBC Driver][Informix]Illegal attempt to convert Text/Byte blob type.
error driver msg : QODBC3: Unable to execute statement