can't start disk defragmenter in vista with sp1

Disk Defragmenter NTFS Module

Stopped working

2008/3/28 13:34

Report Sent

Problem signature
Problem Event Name: APPCRASH
Application Name: DfrgNtfs.exe
Application Version: 6.0.6001.18000
Application Timestamp: 4791915f
Fault Module Name: StackHash_5418
Fault Module Version: 6.0.6001.18000
Fault Module Timestamp: 4791adec
Exception Code: c0000374
Exception Offset: 00000000000a6e97
OS Version: 6.0.6001.
Locale ID: 2052
Additional Information 1: 5418
Additional Information 2: c71202947f7aede455380a07a141fd7e
Additional Information 3: 24b5
Additional Information 4: 782a2a3c920d20533c4890a90d83659f

Extra information about the problem
Bucket ID: 1067524