Error: Attempted to read or write protected memory (while filling a datareader)

[HairyMonkeyMan]

Hello all,

I am having a problem with some code, and haven't been able to work it out on my own . Hopefully one of you nice people can help me clear this up .

Here is the code:

    Private Sub BindSummary()
        Dim _sql As String = "SELECT * FROM [qry_Project_ProjectedFee_Summary] WHERE [Month/Year] = ? ORDER BY [Name]"
        Dim _dbConn As New OleDbConnection(ConfigurationManager.ConnectionStrings("MyDbConn1").ToString)
        Dim _dbComm As New OleDbCommand(_sql, _dbConn)
        
        _dbComm.Parameters.Add(New OleDbParameter("[Month/Year]", CDate(lstCurrentMonth.SelectedItem.Value)))
        
        _dbComm.Connection.Open()
        
        Summary.DataSource = _dbComm.ExecuteReader
        Summary.DataBind()
        _dbComm.Connection.Close()
        
        ' Get Totals
        _sql = "SELECT SUM(Total) AS Total, SUM(Claimed) AS Claimed, SUM(Initial) - SUM(SubInitial) AS Initial" & _
               ", SUM(Actual) - SUM(Actual) AS Actual, SUM(Revised) - SUM(SubRevised) AS Revised" & _
               ", SUM(Future1) - SUM(SubFuture1) AS Future1, SUM(Future2) - SUM(SubFuture2) AS Future2" & _
               ", SUM(Remaining) - SUM(SubRemaining) AS Remaining " & _
               "FROM(qry_Project_ProjectedFee_Summary) WHERE [Month/Year] = ?"
        
        _dbComm.CommandText = _sql

        _dbComm.Parameters.Add(New OleDbParameter("[Month/Year]", CDate(lstCurrentMonth.SelectedItem.Value)))
        _dbComm.Connection.Open()
        
        Dim _dbRead As OleDbDataReader = _dbComm.ExecuteReader()

        _dbComm.Connection.Close()
        
        _CurrentMonth = lstCurrentMonth.SelectedItem.Value

        _dbRead = Nothing
        _dbComm = Nothing
        _dbConn = Nothing
    End Sub

The error occurs at the code in bold.

This is the exact error:

Server Error in '/' Application.
--------------------------------------------------------------------------------

Attempted to read or write protected memory. This is often an indication that other memory is corrupt. 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

Source Error: 


Line 89:         _dbComm.Connection.Open()
Line 90:         
Line 91:         Dim _dbRead As OleDbDataReader = _dbComm.ExecuteReader()
Line 92: 
Line 93:         _dbComm.Connection.Close()
 

Source File: C:\Inetpub\pmacs\FeeProjection.aspx    Line: 91 

Stack Trace: 


[AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.]
   System.Data.Common.IAccessor.ReleaseAccessor(IntPtr hAccessor, Int32& pcRefCount) +0
   System.Data.OleDb.RowBinding.Dispose() +90
   System.Data.OleDb.Bindings.Dispose() +29
   System.Data.OleDb.OleDbCommand.InitializeCommand(CommandBehavior behavior, Boolean throwifnotsupported) +46
   System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult) +16
   System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method) +106
   System.Data.OleDb.OleDbCommand.ExecuteReader(CommandBehavior behavior) +111
   System.Data.OleDb.OleDbCommand.ExecuteReader() +6
   ASP.FeeProjection_aspx.BindSummary() in C:\Inetpub\pmacs\FeeProjection.aspx:91
   ASP.FeeProjection_aspx.lstCurrentMonth_SelectedIndexChanged(Object sender, EventArgs e) in C:\Inetpub\pmacs\FeeProjection.aspx:129
   System.Web.UI.WebControls.ListControl.OnSelectedIndexChanged(EventArgs e) +105
   System.Web.UI.WebControls.ListBox.RaisePostDataChangedEvent() +132
   System.Web.UI.WebControls.ListBox.System.Web.UI.IPostBackDataHandler.RaisePostDataChangedEvent() +7
   System.Web.UI.Page.RaiseChangedEvents() +137
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5330

 


--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:2.0.50215.44; ASP.NET Version:2.0.50215.44

It seems like no matter what I do, the .ExecuteReader method always fails.
I have tried creating a new command object for the second execution of executereader, but I still had the same error.

Any help, much appreciated