ReleaseHandleFailed Exception

I have just got the following bloody MDA exception on a rather simple little program:

A SafeHandle or CriticalHandle of type 'Microsoft.Win32.SafeHandles.SafeCapiHashHandle' failed to properly release the handle with value 0x004E48C0. This usually indicates that the handle was r开发者_StackOverflow中文版eleased incorrectly via another means (such as extracting the handle using DangerousGetHandle and closing it directly or building another SafeHandle around it.)

I have never seen anything like this. My program code is:

public partial class SmsEditorForm : Form
{
    public SmsEditorForm()
    {
        InitializeComponent();
    }

    private void SmsEditorForm_Load(object sender, EventArgs e)
    {          
        using (var ents = new TemplateEntities())
        {
            templateCombo.DataSource = ents.NotificationTemplates.OrderBy(nt => nt.TemplateName).ToList();
            jobCardCombo.DataSource = ents.JobCards.Where(jc => !jc.JobDeleted && !jc.Archived).ToList();
        }
    }

    private void smsText_TextChanged(object sender, EventArgs e)
    {
        charCountLabel.Text = smsText.Text.Trim().Length.ToString();
    }

    private void templateCombo_SelectedIndexChanged(object sender, EventArgs e)
    {
        using (var ents = new TemplateEntities())
        {
            smsText.Text = ents.NotificationTemplates.Single(nt => nt.TemplateId == (int) templateCombo.SelectedValue).ExternalRecipientSms;
        }
    }
}

Looks like a problem in your SMS library. In particular, whatever part of the code uses SafeCapiHashHandle (this is an encryption handle, so, e.g., using a web service over SSL would cause this).