I wrote this function to download html text, but the problem I'm having is it seems to be reading it from a hidden cache.

Code:
Private Declare Function InternetCloseHandle Lib "wininet.dll" (ByVal hInet As Long) As Integer
Private Declare Function InternetOpen Lib "wininet.dll" Alias "InternetOpenA" (ByVal sAgent As String, ByVal lAccessType As Long, ByVal sProxyName As String, ByVal sProxyBypass As String, ByVal lFlags As Long) As Long
Private Declare Function InternetOpenUrl Lib "wininet.dll" Alias "InternetOpenUrlA" (ByVal hOpen As Long, ByVal sUrl As String, ByVal sHeaders As String, ByVal lLength As Long, ByVal lFlags As Long, ByVal lContext As Long) As Long
Private Declare Function InternetReadFile Lib "wininet.dll" (ByVal hFile As Long, ByVal sBuffer As String, ByVal lNumBytesToRead As Long, lNumberOfBytesRead As Long) As Integer

Public Function DownloadURL(ByVal URL As String) As String
    Const INTERNET_OPEN_TYPE_PRECONFIG = 0
    Const INTERNET_OPEN_TYPE_DIRECT = 1
    Const INTERNET_OPEN_TYPE_PROXY = 3
    Const scUserAgent = "VB Project"
    Const INTERNET_FLAG_RELOAD = &H80000000
    Dim lngOpen As Long
    Dim lngOpenURL As Long
    Dim blnReturn As Boolean
    Dim strReadBuffer As String * 2048
    Dim lngNumberOfBytesRead As Long
    Dim strBuffer As String

    lngOpen = InternetOpen(scUserAgent, INTERNET_OPEN_TYPE_PRECONFIG, vbNullString, vbNullString, 0)
    lngOpenURL = InternetOpenUrl(lngOpen, URL, vbNullString, 0, INTERNET_FLAG_RELOAD, 0)
    Do
        strReadBuffer = vbNullString
        blnReturn = InternetReadFile(lngOpenURL, strReadBuffer, Len(strReadBuffer), lngNumberOfBytesRead)
        strBuffer = strBuffer & Left$(strReadBuffer, lngNumberOfBytesRead)
        If Not CBool(lngNumberOfBytesRead) Then Exit Do
    Loop
    If lngOpenURL <> 0 Then InternetCloseHandle (lngOpenURL)
    If lngOpen <> 0 Then InternetCloseHandle (lngOpen)
    DownloadURL = strBuffer
End Function
Here's what I did:

1) Ran my function to grab a wiki page.
2) Manually corrected some text on that same wiki page using Firefox.
3) Manually cleared all internet cache on Internet Explorer.
4) Manually cleared all internet cache on Firefox. (Just because.)
5) Re-ran my function to grab the new corrected version of that same wiki page.

The function is still returning the original text, from before I made the changes in step 2. If I go to the page in Firefox I get the new correct text, but for whatever reason my function is returning the old text.

I also notice that Internet Explorer (11) is showing the old text when I go to the page, even though I deleted all my cache. I manually Ctrl+F5'ed to force a refresh, but still no joy. Still in IE11, I chose Edit Page and the edit text shows the correct text. If I now hit the Back button, IE11 finally shows the correct text. But even after all that, my function still returns the old text.

Please help! There's something like 75 pages that I crawl, and there's no way I can manually do all that hoop-jumping each time I need to update my data. Especially since I don't know what may or may not have changed, as (obviously) I'm not the only person who maintains this particular wiki.