Is It a BUG about IPersistStreamInit::Load()

hi,all
why the IWebBrowse2 rendered failed after the
IPersistStreamInit::Load()
of IHTMLDocument2 load IStream successfully, sometimes the IE show
normally with html format,sometimes the IE show only plain text format.


my intention:
I download the webpage and create IWebBrowse2 interface ,and I
need to show the webpage in IE view. get the IHTMLDocument2 interafce.

my appendant questions:
1 When I get the IHtmldocument body with get_body, the result is
the whole html of the webpage sometimes,is not the <body>...</bady>
tag fragment.
2. how long I have to wait when the IE finish readering.
3. Can I use the IWebBrowse2 interface function if the IE fail to
readering.

.