Oracle Database Discussions

I have a problem with creating a connection to a Oracle 10g Database. I installed Oracle Client 10g.
I have a C++ program an work with the Microsoft Visual C++ .NET 2005.
My problem refers to the following code:



string user = "xx";
string passwd = "ww";
string db = "qq";


Environment *env;
Connection *con;
Statement *stmt;


env = Environment::createEnvironment(Environment::DEFAULT);
con = env->createConnection(user, passwd, db);



ERROR DESCRIPTION:

Error number: 24960


ORA-24960: the attribute OCI_ATTR_USERNAME is greater than the maximum allowable length of 255


OCIAttrGet with OCI_ATTR_USERNAME = -2


New Oracle C++ Call Interface (OCCI) libraries are available for Microsoft Visual C++ .NET 2005 ??

Thanks!!