SQL OCI QSqlDatabase.tables() does not work

I installed Oracle 11g under windows, setup all connections and then create a table (user system, password my choice).
I can access these table with sql pro, can add data and selects, but using QSqlDatabase::tables() does not have this table in the Stringlist.
Using a tool dbvisualizer shows that table correctly under SYSTEM TABLES.
I got about 1500 entries in the list, using the parameter QSql::AllTables in .tables() brings about 4500 entries, but not my table.

QSqlDatabase db = QSqlDatabase::addDatabase("QOCI");
dp.open("system", "mypassword");
QSqlQuery query("CREATE TABLE mytable (NAME VARCHAR(20))");
table is created
QSqlQuery query1("INSERT into mytable....")
Select shows data

QStringList List = db.tables() (or db.tables(QSql::AllTables))
mytable is not found....