You are troubleshooting IM Manager for Sametime.  You need to determine what information the ST Chat Logging service service is processing. 

NOTE:  This information is provided as a courtesy.  Please use official IBM documentation and support resources for more information.

1. Open the file C:\Program Files\IBM\Lotus\Domino\sametime.ini in an editor.
2. Add the following entries in the Debug section like this:

[Debug] 
VP_DEBUG_CHAT_LOGGING=1 
VP_OM_LOGGING=1 
IM_CHANNEL=1

3. Save the sametime.ini file.
4. Stop the Sametime services.
5. Start the Sametime services.

The debug output for the ST Chat Logging service is in the file c:\program files\ibm\lotus\domino\trace\StChatLogging_<datetime>.txt.  The filenames contain the date and time like this example: StChatLogging_110929_1124_3496_000.txt.

The following is an example from the debug log of a message sent from johndoe to ben SYSTEM:

111017_134202,INF,ChatLogg,ChatLoggingMgr::CheckSessionPolicy: userId <johndoe> toUserId <CN=ben SYSTEM/O=blackopssimm>
111017_134202,INF,OmChatLo,ClCnlMgr::canAcceptChannel: session between <johndoe> and <CN=ben SYSTEM/O=blackopssimm> is permitted
111017_134202,INF,ChatLogg,ChatLoggingMgr::startSession: sessionId <5> organization <>
111017_134202,INF,ChatLogg,bbHandler::sessionStarted: success...
111017_134202,INF,ChatLogg,ChatLoggingMgr::OmUserJoinedSession: sessionId <5> userId <CN=ben SYSTEM/O=blackopssimm>
111017_134202,INF,ChatLogg,bbHandler::userJoinedSession: success...
111017_134202,INF,OmChatLo,ClImChannel::created: First user joined session <5> with dda result <0>
111017_134202,INF,ChatLogg,ChatLoggingMgr::OmUserJoinedSession: sessionId <5> userId <johndoe>
111017_134202,INF,ChatLogg,bbHandler::userJoinedSession: success...
111017_134202,INF,OmChatLo,ClImChannel::created: Second user joined session <5> with dda result <0>
111017_134202,INF,OmChatLo,ClImChannel::created: Session 5 started
111017_134202,INF,OmChatLo,ClImChannel::created: User <CN=ben SYSTEM/O=blackopssimm> and User <johndoe> joined the session
111017_134202,INF,ChatLogg,ChatLoggingMgr::OmDataMsgFromMember: sessionId <5> senderId <johndoe> receiverId <CN=ben SYSTEM/O=blackopssimm>
111017_134202,INF,ChatLogg,ChatLoggingMgr::OmDataMsgFromMember: sessionId <5> senderId <CN=ben SYSTEM/O=blackopssimm> receiverId <johndoe>
111017_134204,INF,ChatLogg,ChatLoggingMgr::OmDataMsgFromMember: sessionId <5> senderId <johndoe> receiverId <CN=ben SYSTEM/O=blackopssimm>
111017_134204,INF,ChatLogg,ChatLoggingMgr::OmMsgFromMember: sessionId <5> senderId <johndoe> receiverId <CN=ben SYSTEM/O=blackopssimm>
111017_134205,INF,ChatLogg,bbHandler::sessionMsg: success...
111017_134205,INF,OM      ,IMChannel::sendText: encrypt = <true>
111017_134205,INF,ChatLogg,ChatLoggingMgr::OmDataMsgFromMember: sessionId <5> senderId <johndoe> receiverId <CN=ben SYSTEM/O=blackopssimm>
111017_134242,INF,ChatLogg,ChatLoggingMgr::OmUserLeftSession: sessionId <5> userId <johndoe>
111017_134242,INF,ChatLogg,bbHandler::userLeftSession: success...
111017_134242,INF,ChatLogg,ChatLoggingMgr::OmUserLeftSession: sessionId <5> userId <CN=ben SYSTEM/O=blackopssimm>
111017_134242,INF,ChatLogg,bbHandler::userLeftSession: success...
111017_134242,INF,ChatLogg,ChatLoggingMgr::endSession: sessionId <5>
111017_134242,INF,ChatLogg,bbHandler::sessionEnded: success...

The following debug log message shows the ST Chat Logging Service sending the message to the STChatLog.dll, typically IM Manager:

111017_134205,INF,OM      ,IMChannel::sendText: encrypt = <true>

 If this message is not present then the message is not presented to IM Manager and therefore IM Manager does not process the message.