Memory very slow to release on class level object

I have found what seems to be be strange behavior in VB6.  If I declare an object at the class level, when I try to destroy it, it takes a very long time, 80 seconds. But if I declare this object within a Sub and destroy it releases the memory in less than one second.  This object reads in a 5mb file.  Below is some code and the output:

Public m_objDataObject As MyObject

Private Sub cmdCreateandDestory_Click()

    '' Test Local Object create and destoy
    Dim dtmStartTime As Date
    Dim dtmDiff  As Date
   
    Debug.Print "Creating local object"
   
    dtmStartTime = Now
    Dim objMyObject As MyObject
    Set objMyObject = New MyObject
    objMyObject.LoadData

    Debug.Print " Creation took " + CStr(DateDiff("s", dtmStartTime, DateTime.Now)) + " secs"

    dtmStartTime = DateTime.Now
    Debug.Print " Destroying local object"
    Set objMyObject  = Nothing
    Debug.Print " Destroying local object took " + CStr(DateDiff("s", dtmStartTime, DateTime.Now)) + " secs"
    Debug.Print
    ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
   
    '' Test global create and destroy
    Debug.Print "Creating class object"
   
    dtmStartTime = Now
    Set m_objDataObject = New MyObject
    m_objDataObject.LoadData
   
    Debug.Print " Creation took " + CStr(DateDiff("s", dtmStartTime, DateTime.Now)) + " secs"
     
    dtmStartTime = DateTime.Now
    Debug.Print " Destroying global object"
    Set m_objDataObject = Nothing
   
    Debug.Print " Destroying global object took " + CStr(DateDiff("s", dtmStartTime, DateTime.Now)) + " secs"
End Sub

Creating local object
 Loading data from file took 0 secs
7/21/2008 11:36:29 AM
 Creation took 7 secs
 Destroying local object
 Destroying local object took 0 secs

Creating global object
 Loading data from file took 1 secs
7/21/2008 11:36:40 AM
 Creation took 11 secs
 Destroying global object
 Destroying global object took 78 secs