Kevin,
Could you see anything in this output that would cause the message "Object reference not set to an instance of an object."?

at McFaddens.RadAuditUtility.Business.AccountsPayableMasterDetailByVendor.HookParentRetrieved(mmBusinessObject bizObj, mmBusinessStateChangeEventArgs e) in c:\documents and settings\theo\my documents\visual studio projects\mcfaddens\mcfapplication\radaudit utility business objects\accountspayable\accountspayablemasterdetailbyvendor.cs:line 72
at OakLeaf.MM.Main.Business.mmBusinessObject.StateChangeHandler(mmBusinessObject bizObj, mmBusinessStateChangeEventArgs e)
at OakLeaf.MM.Main.Business.mmBusinessStateChangeDelegate.Invoke(mmBusinessObject bizObj, mmBusinessStateChangeEventArgs e)
at OakLeaf.MM.Main.Business.mmBusinessObject.OnStateChange(mmBusinessState bizState, String tableName, Object primaryKeyValue, Object[] primaryKeyValues)
at OakLeaf.MM.Main.Business.mmBusinessObject.CallStateChange(mmBusinessState bizState, String tableName)
at OakLeaf.MM.Main.Business.mmBusinessObject.FillDataSet(DataSet ds, String command, String tableName, String databaseKey, CommandType cmdType, IDbDataParameter[] dataParams)
at OakLeaf.MM.Main.Business.mmBusinessObject.GetDataSet(String command, String tableName, String databaseKey, CommandType cmdType, IDbDataParameter[] dataParams)
at OakLeaf.MM.Main.Business.mmBusinessObject.GetDataSet(String command, String tableName, String databaseKey, IDbDataParameter[] dataParams)
at OakLeaf.MM.Main.Business.mmBusinessObject.GetDataSet(String command, String tableName, String databaseKey)
at OakLeaf.MM.Main.Business.mmBusinessObject.GetDataSet(String command, String tableName)
at OakLeaf.MM.Main.Business.mmBusinessObject.GetDataSet(String command)
at McFaddens.RadAuditUtility.Business.AccountsPayableReconciliationByVendorItems.GetAllAccountsPayableReconciliationItemsByVendor() in c:\documents and settings\theo\my documents\visual studio projects\mcfaddens\mcfapplication\radaudit utility business objects\accountspayable\accountspayablereconciliationbyvendoritems.cs:line 36
at McFaddens.RadAuditUtility.AccountsPayableReconciliationByVendorForm.btnAccountsReceivablesReconciliationByCustomerGetCustomers_Click(Object sender, EventArgs e) in c:\documents and settings\theo\my documents\visual studio projects\mcfaddens\mcfapplication\radaudit utility\accountspayablereconciliationbyvendorform.cs:line 341
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.ComponentManager.System.Windows.Forms.UnsafeNativeMethods+IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(Form mainForm)
at McFaddens.RadAuditUtility.Main.AppMainEntry.Main() in c:\documents and settings\theo\my documents\visual studio projects\mcfaddens\mcfapplication\radaudit utility\main.cs:line 45