Strage classloading behaviour of JDBC driveres

Hi, 

It seems to be some classloading weirdness while running plugin in sandbox.    I have dependency on JDBC driver ( statet as plugin dependency ), and to be able to create connection I have to load driver manualy first:

try {
    System.err.println(Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver") );
} catch (ClassNotFoundException e) {
    e.printStackTrace();
}
// create db connection
Properties connectionProps = new Properties();
connectionProps.put("user", pmFacet.getConfiguration().getUsername());
connectionProps.put("password", pmFacet.getConfiguration().getPassword());

System.err.println("created properties");
try {
    String databaseConnection = pmFacet.getConfiguration().getDatabaseConnection();
    final Connection connection = DriverManager.getConnection(databaseConnection, connectionProps);

Without is, connection fails on driver not found.   Usially it is expected to work out of the box,   but I also tried:

-Djdbc.drivers=com.microsoft.sqlserver.jdbc.SQLServerDriver

and also adding jar file to IDEA sdk Classloasder -  nothing seems to work, and delivers CNFE.   What would be a proper way to do this?