Only part of response returned (sometimes) (General questions)

I am using dot net 2003 and am having a problem returning a page. At first I thought it was due to RunScript not populating the resonse correctly but I am able to get it to happen (1 of 5 times) with just a static htm doc. The page is truncated in a different position each time. More code can be provided if needed:

Private Sub http1_RequestDone(ByVal e As WODWEBSERVERLib.WebUser) Handles http1.RequestDone
Dim a As String
Dim theshowfile As String
Dim Scr_hDC As Long
Dim startdoc As Long
Dim thefilename As String
Dim x As Integer

a = webfiledir
e.Response.ScriptBegin = <
e.Response.ScriptEnd = >
If File.Exists(a + e.Request.PageName) Then
a = a & e.Request.PageName

Else
If e.Request.PageName = Then
a = a & index.htm
Else
a = a + handlescript(e.Request.PageName, e)
End If
End If

' is there such a file?
If File.Exists(a) Then
Junk.Text = theGuts
e.Response.Filename = a
e.Response.StatusCode = 200

Else
' return 404 not found
e.Response.StatusCode = 404
End If
' e.user.Response.Send()
End Sub