Driver's SQLSetConnectAttr Failed

I have an application that uses an odbc to connect at a database informix ids9.30
The test connect in odbc is ok
 
but when i launch the application I get an error:
 
"entry database= is empty or missing in odbc connectstring.."
 
I ran a trace in the ODBC saw this from SQL.LOG...
DIAG [IM006] [Microsoft][Gestionnaire de pilotes ODBC] Driver's SQLSetConnectAttr Failed (0)
 
 
microsoft  give me no information on how to solve the problem
 
http://msdn.microsoft.com/library/default.asp?url="">
 
Any idea ?
Many thanks