ASP.NET 2.0.50727.0 Event code: 3005

Every day at 12:00AM I get these error messages and they continue every minute until I restart IIS.  The asp code that this error message is complaining about runs perfectly all day, until midnight, then bam I'm getting spammed with these errors.

Event Type:      Warning
Event Source:      ASP.NET 2.0.50727.0
Event Category:      Web Event
Event ID:      1309
Date:            3/7/2008
Time:            12:01:05 AM
User:            N/A
Computer:      W
Description:
Event code: 3005
Event message: An unhandled exception has occurred.
Event time: 3/7/2008 12:01:05 AM
Event time (UTC): 3/7/2008 5:01:05 AM
Event ID: 792f3cdeed404061aea648d7d188e050
Event sequence: 17800
Event occurrence: 13
Event detail code: 0
 
Application information:
    Application domain: /LM/W3SVC/1/Root/DundasReport-2-128493297932102944
    Trust level: Full
    Application Virtual Path: /DundasReport
    Application Path: D:\Dundas Projects\DUNDAS_RealTime_WebApp\
    Machine name: W
 
Process information:
    Process ID: 7920
    Process name: w3wp.exe
    Account name: NT AUTHORITY\NETWORK SERVICE
 
Exception information:
    Exception type: InvalidCastException
    Exception message: Conversion from type 'DBNull' to type 'Double' is not valid.
 
Request information:
    Request URL: http://ecrpt/dundasreport/SHOPPING_frequency2.aspx
    Request path: /dundasreport/SHOPPING_frequency2.aspx
    User host address: 10.181.107.171
    User:  
    Is authenticated: False
    Authentication Type:  
    Thread account name: NT AUTHORITY\NETWORK SERVICE
 
Thread information:
    Thread ID: 9
    Thread account name: NT AUTHORITY\NETWORK SERVICE
    Is impersonating: False
    Stack trace:    at Microsoft.VisualBasic.CompilerServices.Conversions.ToDouble(Object Value, NumberFormatInfo NumberFormat)
   at Microsoft.VisualBasic.CompilerServices.Conversions.ToDouble(Object Value)
   at WebApplication7.WebForm1.Page_Load(Object sender, EventArgs e)
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
 
 
Custom event details:

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