CreateObject("Microsoft.XMLHTTP")

I've just recently (as of this week) run into a strange issue I've never seen before and am hoping that the VBForum gurus can assist. (PLEASE)

I have been submitting webservice requests via XMLHTTP for several years now with absolutely no issue until now. I have multiple functions that submit SOAP requests and now I am running into my requests are returned as "Access is Denied" randomly and once it happens the only way to "clear it up" is to close down the program and reopen or if I'm in VB6 I have to close the VB6 app completely and reopen.

My code is very straightforward:

With CreateObject("Microsoft.XMLHTTP")
.Open "Get", Form1.ShareURL & "_vti_bin/Lists.asmx?r=" & Rnd, False, Null, Null
.setRequestHeader "Content-Type", "text/xml; charset=utf-8"
.setRequestHeader "SOAPAction", "http://schemas.microsoft.com/sharepoint/soap/UpdateListItems"
.Send Request_XML
Mass_Assign = .responsetext
End With

I added the r= & rnd to see if it helps but it does not.

As you can see I'm passing Null, Null to user/password. Why would it get stuck returning Access is Denied for the duration of the application (VB6 in editor or stand alone executable)? Am I supposed to do something to clear the cache out or close the session out somehow?

Help!