We know nothing of the table involved.  Could you at least post the CREATE TABLE statement being sure to include any and all constraints, indexes, and triggers.  I have an idea but it's a total waste of time to bring it up without knowing those things.  I also need to know what the average CPU, Duration, and Logical Reads for that bit of code is and whether or not that bit of code is embedded in an explicit BEGIN TRANSACTION.  It would also be good to know how many rows are currently in the table.