insert clob into table

I have got table with many fields - including clob. And I would like to put data using INSERT command from C++ using OCCI. example below (not working :()

Clob clob(conn); //existing connection object string s("looooong string"); // assume that this string is 8k long int s_size=s.length();
clob.setEmpty();
string sql="INSERT INTO tbl (string_col, clob_col) VALUES (:1,:2)"; stmt->setSQL(sql);
stmt->setString(1,"aaaa");
clob.write(s_size,(unsigned char *)s.c_str(),s_size); stmt->setClob(2,clob);
stmt->executeUpdate();

And this is not working.I get error
ORA-22275: invalid LOB locator specified :(
If I changed lines

clob.write(s_size,(unsigned char *)s.c_str(),s_size); stmt->setClob(2,clob);

to

stmt->setString(2,s);

clob field has only part of string s value :(

primary key is timestamp field and is set to default TIMESTAMP_NOW so I cannot get it's value :(

database is on another server then client I run so I prefer not to set primary key to client local timestamp which can be different from server one.
I'm using Oracle 9i database and client. Please help! Received on Wed Mar 01 2006 - 08:47:29 CST