Sporadic but periodic slow Inserts into a table - Why you should apply SQL Server 2005 SP2

Analyzing a SQL Query trace with SAP’s ST05 SQL Trace, a pattern could be observed which looks like several inserts into a specific table taking place as expected in the milliseconds range but suddenly one inserting query takes hundreds of milliseconds up to a few seconds. Afterwards inserts are back to normal millisecond times and suddenly a long one happens again. One can see a nice pattern of periodic long inserts. Looking at a ST05 output which got consolidated in Excel, the situation could look like: