Shaerpoint Security Exception

[cvsu...@gmail.com]

BAS Messaging fails with Security Exception

Hi All,
I am having an Orchestratio that uses Business Activity Services (BAS)
for manging the partners.
I found a peculiar problem with the BAS mesages sent to the Inbox and
Sent items failing due to a Security Exception. It does not exacly
mention what is the exception.
The event log says:
--------------------------------------------------------------------------------------------

--------------------------------
Security error.
System.Security.SecurityException: Security error.

Server stack trace:
at
Microsoft.BizTalk.KwTpm.StsBizTalkAdapter.IStsAdapter.SendMessageToSts(String

partnerId, String envelopedMessage, String folderType)
at
System.Runtime.Remoting.Messaging.StackBuilderSink.PrivateProcessMessage(MethodBase

mb, Object[] args, Object server, Int32 methodPtr, Boolean
fExecuteInContext, Object[]&

outArgs)
at
System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage
msg,

Int32 methodPtr, Boolean fExecuteInContext)

Exception rethrown at [0]:
at
System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage
reqMsg,

IMessage retMsg)
at
System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData&
msgData, Int32

type)
at
Microsoft.BizTalk.KwTpm.StsBizTalkAdapter.StsAdapter.SendMessageToSts(String

partnerId, String envelopedMessage, String folderType)
at
Microsoft.BizTalk.KwTpm.StsWebReceive.StsWebReceivePage.Page_Load(Object
sender,

EventArgs e)
--------------------------------------------------------------------------------------------

--------------------------------

The BAS messages works well on the Test Servers and I have made sure
the following.

1. StsWebReceive Application path - under def website - has been
excluded from Sharepoint
2. The application runs in a pool which has an indentity that is a part
of all BizTalk

groups, IIS_WPG, STS_WPG. Addiitonally this ac is an admin on this
computer.
3. It runs under the Windows authentication
4. I made a simple aspx page to check the identity of the logged in
user to this

application. This is done as I found that the Web.config of this
application does some

"impersonation" which points to some registry entry. But this is the
correct account only.

The "StsWebReceivePage.aspx" is a Sharepoint page and we donot have the
source of that and

hence canot debug.

Any help to crack this is highly appreciated.

Thanks!
Sudheer