WebBrowser com exception

[Sharon]

Hi all.
Since System.Windows.Forms.WebBrowser is a com wrapper, I'm posting this
here.
Using the WebBrowser class, sometimes i get this exception:

[COMException (0x80004005): Error HRESULT E_FAIL has been returned from a
call to a COM component.]
System.Windows.Forms.IWebBrowser2.Navigate2(Object& URL, Object& flags,
Object& targetFrameName, Object& postData, Object& headers) +0
System.Windows.Forms.WebBrowser.PerformNavigate2(Object& URL, Object&
flags, Object& targetFrameName, Object& postData, Object& headers) +63
System.Windows.Forms.WebBrowser.PerformNavigateHelper(String urlString,
Boolean newWindow, String targetFrameName, Byte[] postData, String headers)
+102
System.Windows.Forms.WebBrowser.set_Url(Uri value) +72
System.Windows.Forms.WebBrowser.set_DocumentStream(Stream value) +76
System.Windows.Forms.WebBrowser.set_DocumentText(String value) +202

When i get this exception i have to reboot my machine, for the component to
work again.
The exception is generated by this line: webBrowser1.DocumentText = "";
And only when used from Asp.net page, console or form work fine.
Any guide would be appreciated.
Sharon.