Sometime when searching for certain keyword, I get this error "Instant Search encountered a problem while trying to display search results. Modifying your query may resolve this problem."

I have enabled Outlook logging to determine what is the error as suggested by someone in other forum. but I haven't had a clue how to decipher it.

2010.05.11 09:38:10 <<<< Logging Started (level is LTF_TRACE) >>>>
2010.05.11 09:38:10 HELPER::Initialize called
2010.05.11 09:38:10 Initializing: Finding a Transport
2010.05.11 09:38:10 MAPI XP Call: XPProviderInit in EMSMDB.DLL, hr = 0x00000000
2010.05.11 09:38:10 MAPI XP Call: TransportLogon, hr = 0x8004011d
2010.05.11 09:38:10 MAPI XP Call: Shutdown, hr = 0x00000000
2010.05.11 09:38:10 MAPI XP Call: XPProviderInit in EMSMDB.DLL, hr = 0x00000000
2010.05.11 09:38:10 MAPI Status: (-- -- ---/--- -- ---)
2010.05.11 09:38:10 MAPI XP Call: TransportLogon, hr = 0x00000000
2010.05.11 09:38:10 Initializing: Found a transport, Error code = 0x00000000
2010.05.11 09:38:10 MAPI XP Call: AddressTypes, hr = 0x00000000, cAddrs = 4, cUids = 1
2010.05.11 09:38:10 MAPI XP Call: RegisterOptions, hr = 0x00000000, cOptions = 2
2010.05.11 09:38:10 MAPI Status: (IN -- ---/OUT -- ---)
2010.05.11 09:38:10 MAPI XP Call: TransportNotify(BEGIN_IN|BEGIN_OUT), hr = 0x00000000
2010.05.11 09:38:10 HELPER::Initialize done, Error code = 0x00000000
2010.05.11 09:38:10 HELPER::GetCapabilities called, Error code = 0x00000000
2010.05.11 09:38:10 Microsoft Exchange: Synch operation started (flags = 00000031)
2010.05.11 09:38:10 Microsoft Exchange: StartImport(flags = 00000000, max msg = ffffffff): full items
2010.05.11 09:38:10 Microsoft Exchange: UploadItems: 0 messages to send
2010.05.11 09:38:11 Starting the Spooling Cycle
2010.05.11 09:38:11 MAPI Status: (IN fl ---/OUT -- ---)
2010.05.11 09:38:11 MAPI XP Call: FlushQueues, hr = 0x00000000, ulFlushFlags = 0x0000001c
2010.05.11 09:38:11 MAPI XP Call: Poll, hr = 0x00000000, cPollCount = 855
2010.05.11 09:38:11 Progress: Receiving message (message 1 out of 856, size unknown)
2010.05.11 09:38:11 Downloading one message
2010.05.11 09:38:11 Transport tightly coupled with store, download is NOOP
2010.05.11 09:38:11 Downloading done, Error code = 0x8004010f
2010.05.11 09:38:11 MAPI Status: (IN -- ---/OUT -- ---)
2010.05.11 09:38:11 FINISHED MAPI TASK
2010.05.11 09:38:11 Microsoft Exchange: ReportStatus: RSF_COMPLETED, hr = 0x00000000
2010.05.11 09:38:11 Finishing the Spooling Cycle, Error code = 0x00000000
2010.05.11 09:38:11 EXECUTING EndSession MAPI TASK
2010.05.11 09:38:11 Starting the Simplified Transfer Cycle
2010.05.11 09:38:11 MAPI XP Call: Poll, hr = 0x00000000, iMsgsReceived = 0, cPollCount = 855
2010.05.11 09:38:11 Progress: Receiving message (message 1 out of 856, size unknown)
2010.05.11 09:38:11 Downloading one message
2010.05.11 09:38:11 MAPI Status: (IN -- act/OUT -- ---)
2010.05.11 09:38:11 MAPI Status: (IN -- ---/OUT -- ---)
2010.05.11 09:38:11 Downloading done, Error code = 0x8004010f
2010.05.11 09:38:11 Finishing the Spooling Cycle, Error code = 0x00000000
2010.05.11 09:38:11 FINISHED MAPI TASK
2010.05.11 09:38:11 Microsoft Exchange: ReportStatus: RSF_COMPLETED, hr = 0x00000000
2010.05.11 09:38:11 Microsoft Exchange: Synch operation completed
2010.05.11 10:08:15 Microsoft Exchange: Synch operation started (flags = 00000031)
2010.05.11 10:08:15 Microsoft Exchange: StartImport(flags = 00000000, max msg = ffffffff): full items
2010.05.11 10:08:15 Microsoft Exchange: UploadItems: 0 messages to send
2010.05.11 10:08:16 Starting the Spooling Cycle
2010.05.11 10:08:16 MAPI Status: (IN fl ---/OUT -- ---)
2010.05.11 10:08:16 MAPI XP Call: FlushQueues, hr = 0x00000000, ulFlushFlags = 0x0000001c
2010.05.11 10:08:16 MAPI XP Call: Poll, hr = 0x00000000, cPollCount = 858
2010.05.11 10:08:16 Progress: Receiving message (message 1 out of 859, size unknown)
2010.05.11 10:08:16 Downloading one message
2010.05.11 10:08:16 Transport tightly coupled with store, download is NOOP
2010.05.11 10:08:16 Downloading done, Error code = 0x8004010f
2010.05.11 10:08:16 MAPI Status: (IN -- ---/OUT -- ---)
2010.05.11 10:08:16 FINISHED MAPI TASK
2010.05.11 10:08:16 Microsoft Exchange: ReportStatus: RSF_COMPLETED, hr = 0x00000000
2010.05.11 10:08:16 Finishing the Spooling Cycle, Error code = 0x00000000
2010.05.11 10:08:16 EXECUTING EndSession MAPI TASK
2010.05.11 10:08:16 Starting the Simplified Transfer Cycle
2010.05.11 10:08:16 MAPI XP Call: Poll, hr = 0x00000000, iMsgsReceived = 0, cPollCount = 858
2010.05.11 10:08:16 Progress: Receiving message (message 1 out of 859, size unknown)
2010.05.11 10:08:16 Downloading one message
2010.05.11 10:08:16 MAPI Status: (IN -- act/OUT -- ---)
2010.05.11 10:08:16 MAPI Status: (IN -- ---/OUT -- ---)
2010.05.11 10:08:16 Downloading done, Error code = 0x8004010f
2010.05.11 10:08:16 Finishing the Spooling Cycle, Error code = 0x00000000
2010.05.11 10:08:16 FINISHED MAPI TASK
2010.05.11 10:08:16 Microsoft Exchange: ReportStatus: RSF_COMPLETED, hr = 0x00000000
2010.05.11 10:08:16 Microsoft Exchange: Synch operation completed
2010.05.11 10:09:48 HELPER::Uninitialize called
2010.05.11 10:09:48 MAPI Status: (-- -- ---/--- -- ---)
2010.05.11 10:09:48 MAPI XP Call: TransportNotify(END_IN|END_OUT), hr = 0x00000000
2010.05.11 10:09:48 MAPI XP Call: TransportLogoff in EMSMDB.DLL, hr = 0x00000000
2010.05.11 10:09:48 MAPI XP Call: Shutdown, hr = 0x00000000
2010.05.11 10:09:48 Resource manager terminated

I'm running Outlook 2007 SP1 in Citrix environment and should be running in Cache Mode. In my Outlook Tools->Options->Search Option, there is nothing under indexing.

Any help is greatly appreciated! Thank you.