I´m not sure you are talking about me :
But I use the Steve Gibson’s programs (including DCOMbobulator) in a XP Pro SP1 system without any fear or trouble. Waldo said the whole truth: Steve Gibson’s programs (utils) are always recommended in respected security forums (Wilders & DSL,…) So i guess no worries here also… 
On the webpage the DCOM system is fully analysed and described. It is a Microsoft hole for hell 