Security Software

I have installed webgate "Oracle_Access_Manager10_1_4_2_5_Win32_ISAPI_WebGate.exe" (here IIS is the web server),in OAM 10.1.4.3.In the "Access system configuration, i have created a host identifier,created an instance of Access gate then installed the web gate 10.1.4.2.5.OAM installation guide says, to confirm the web gate installation go to the URL "http(s)://hostname:port/access/oblix/apps/webgate/bin/webgate.dll?progid=1", but when i hit this URL, is asks me to enter the username and password credentials (Oracle access and Identity Basic over LDAP login prompt). After entering the credntials, it should take me to the web gate diagnostics page, but the web page says "Page cannot be found".HTTP Error 404, file or directory not found IIS.Here is what the event log warning says:

Event Type: Warning
Event Source: Access Server SDK
Event Category: None
Event ID: 520
Date: 9/28/2011
Time: 12:50:18 PM
User: N/A
Computer: SYM-2K3-148-110
Description:
The description for Event ID ( 520 ) in Source ( Access Server SDK ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description; see Help and Support for details. The following information is part of the event: Logging engine is already configured..

So, how can we overcome this and confirm the web gate installation