If you are STILL using BizTalk Server 2004, then go get the just-released Service Pack 2 (although I suggest you first ask yourself why you have not upgraded to BizTalk Server 2006!).
Overview
Microsoft BizTalk Server 2004 Service Pack 2 contains many important fixes. In addition, a new feature called Archiving and Purging has been added which can automatically manage both the purging and the archiving of the tracking database. Some of the most important fixes that are included in this service pack are:
Performance issues with different orchestration scenarios
EDI transmit fails with certain structures of outgoing messages
Disassembling large flat file messages in the pipeline stalls other processing
The rules engine is not honoring rule priorities correctly in high load
Body tracking doesn’t track the original message
Dynamic send ports causing 10 second delay in subscription
100% CPU in orchestration when calling PrepareForActivationComplete
Messages could still be delivered even though the orchestration instances were zombied
Connection problems with HTTP Request-response requests
Request to turn off FTP Throttling
Memory Leak problem in PipelineContextWrapper/Interop.ResourceTrackerbr
You can find it at:
English:
http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=en
Chinese (Simplified):
http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=zh-cn
Chinese (Traditional):
http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=zh-tw
French:
http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=fr
German:
http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=de
Italian:
http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=it
Japanese:
http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=ja
Korean:
http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=ko
Spanish:
http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=es