TDDS failed to batch execution of streams Warning

We are getting the following warning in our event log anywhere from 1 to 5 
times a day:

Severity:  Warning
Status:  New
Source:  BAM EventBus Service
Name:  Warning: TDDS failed to batch execution of streams
Description:  Execute batch error.  Exception information:  TDDS failed to

batch execution of streams.  SQLServer: server1, Database: 
BizTalkDTADb.Cannot insert duplicate key row in object 
'dta_MessageFieldValues' with unique index 'IX_MessageFieldValues'.
The statement has been terminated..  

This has now been going on for months. Does anyone have any ideas what
this 
is and what it means? Should we be concerned?

Thank you,

Adam Beal