I was building a new custom group of registry entries just now and RegDefend locked up twice. I had to "power switch" reboot to get back to normal. Here's what I did on the building. 1. Created a new group. The new group was Active. 2. Added 10 registry elements for monitoring. 3. Started selecting each element to change "When the following access occurs" and "perform this action". 4. I selected Ask User, Modifying Registry Keys, Modifying Registry Values on the first 4 elements in the order of Ask User, Modifying Registry Keys, and then Modifying Registry Values. 5. On the fifth element I selected Ask User, Modifying Reg Keys and the first lock up occurred. 6. Power Rebooted. 7. Started setting options on remaining elements in the same order as (4). 8. On the 7th element, I selected Ask User, Modifying Reg Keys and the lockup occurred again. 9. Power Rebooted. 10. Deactivated Group and made the remaining settings changes. 11. Reactivated Group. No further lock up. Windows XP-SP2 HE on a 2.6 ghertz P4 (no HT).