Opening multiple reports in Crystal Reports for VS causes database connect limit to be reached. Seems to be no way to force Crystal Reports to close database connection (other than exiting application)

Question

I am working on upgrading an application that has been in use for many years.  The application is written in VB6 and I have been tasked with upgrading the current application to Crystal Reports for Visual Studio.  I am using Crystal Reports for VS Version 13.0.12.1494.  The system's database is a Sybase SQL Anywhere 16 database with an ODBC connection using integrated login.  Each of the reports has the database connection set up from within the report.  There is only once database server, so each of the reports are pointing to the same DB.  The database server is currently installed as a "Personal Server" with a limit of 10 connections. 
I have implemented the CR viewer as part of a COM-callable wrapper that exposes a COM interface for VB6 to interact with.  Inside of my viewer component is a Winform that embeds the Crystal's Report viewer.  The COM interface basically maps the basic Crystal apis to methods that the VB6 can call (i.e., Load Report, Set Field Text, Update SQL Query, etc).  This architecture is working as designed and the reports are displaying correctly and responding correctly to changes in queries, etc.
The issue is that after I open 9 reports, the tenth one will respond with an error indicating that the database connection limit has been reached.  The database connections used by the reports aren't released until after the application is closed.  The application is designed for a secure environment that prohibits the non-administrative user from accessing the systems desktop, so asking the user tor restart the application after 10 reports isn't a viable option.
I have checked and database connection pooling is turned off for the SQL Anywhere 16 driver.
I have been digging on this for a few days and have tried adding code in the FormClosed event to close and dispose of the Report Document as follows:
ReportDocument reportDoc= (ReportDocument) crystalReportViewer1.ReportSource;
reportDoc.Close();
reportDoc.Dispose();
GC.Collect();       // Force garbage collection on disposed items
I have also tried the following (as well as maybe 20 or so other permutations) trying to fix the issue with no success.  
ReportDocument reportDoc= (ReportDocument) crystalReportViewer1.ReportSource;
foreach (Table table in reportDoc.Database.Tables)
     table.Dispose();
crystalReportViewer1.ReportSource = null;
reportDoc.Database.Dispose();
reportDoc.Close();
reportDoc.Dispose();
reportDoc = (ReportDocument)crystalReportViewer1.ReportSource;
GC.Collect();       // Force garabe collection on disposed items
Any ideas or suggestions would be greatly appreciated.  I have been pulling my hair out on this one!

Answer 1

Hi Ludek,
Thanks so much for the quick reply.  Unfortunately I did not have time to work on the reporting project Friday afternoon, but did a quick test this morning with some interesting results.  I'm hoping if I describe what I'm doing, you can show me the error of my ways.  This is really my first major undertaking with Crystal Reports.
If I simply load the report, then close and dispose, I don't hit the limit of 10 files.  Note that I do not logon manually in my code as the logon parameters are all defined within the reports themselves.  The logon happens when you actually view the report.  Loading the report doesn't seem to actually log in to the DB.
What I did was create a very simple form with a single button that creates the WinForm class which contains the Crystal Viewer.  It then loads the report, sets the ReportSource property on the CrystalReportsViewer object contained in the WInForm and shows the report. The report does show correctly, until the 10 reports limit is reached.
The relevant code is shown below. More than I wanted to post, but i want to be as complete and unambiguous as possible. 
This code displays the same behavior as my earlier post (after 10 reports we are unable to create another connection to the DB).
// Initial Form that simply has a button
  public partial class SlectReport : form
        public SelectReport()
            InitializeComponent();
        private void button1_Click(object sender, EventArgs e)
            ReportDocument rd = new ReportDocument();
            ReportForm report = new ReportForm();
            try
                rd.Load(@"Test.rpt");
                report.ReportSource = rd;
                report.Show();
         catch (Exception ex)
              MessageBox.Show(ex.Message);
// The WinForm containing the Crystal Reports Viewer
    public partial class ReportForm : Form
        public ReportForm()
            InitializeComponent();
        private void Form1_Load(object sender, EventArgs e)
            this.crystalReportViewer1.RefreshReport();
            this.FormClosed += new FormClosedEventHandler(ReportForm_FormClosed);
        void ReportForm_FormClosed(object sender, FormClosedEventArgs e)
            ReportDocument rd;
            rd = (ReportDocument)crystalReportViewer1.ReportSource;
            rd.Close();
            rd.Dispose();
        public object ReportSource
            set { crystalReportViewer1.ReportSource = value; }
Again, any guidance would be greatly appreciated.