CachedRowSet Concurrency

I have an application that starts a new process every 15 minutes. I
create a new thread for each process so it is possible that they will
run concurrently. I have a data access layer that returns a
CachedRowSet object. When I only have 1 process running, the program
is fine. As soon as another process starts, I start getting errors in
the data access layer. I get an exception in
"com.sun.rowset.CachedRowSetImpl.populate".
My data access layer method looks like this:

public RowSet retrieve(String sql)
{
    Connection connection = null;
    ResultSet resultset = null;
    CachedRowSet rowset = null;
    Statement statement = null;

    try
    {
       connection = Current.getConnection();
           statement =
connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
           resultset = statement.executeQuery(sql);
           rowset = new CachedRowSetImpl();
       rowset.populate(resultset);
       resultset.close();
       statement.close();
    }
    catch (SQLException sqle)
    {

           sqle.printStackTrace();
    }

    finally
    {
           connection = null;

    }

    return rowset;
}