nsrexecd.exe failed

Hello,

Version 7.6 SP1

I have a problem with the services nsrexecd, when i start a backup the service on the client stop to running and i receive the following error on the eventlog :

Event Type:    Information
Event Source:    Application Error
Event Category:    (100)
Event ID:    1004
Date:        3/31/2011
Time:        2:51:46 PM
User:        N/A
Computer:    NOHBK04
Description:
Reporting queued error: faulting application nsrexecd.exe, version 7.6.1.0, faulting module librpc.dll, version 7.6.1.0, fault address 0x00003454.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Data:
0000: 41 70 70 6c 69 63 61 74   Applicat
0008: 69 6f 6e 20 46 61 69 6c   ion Fail
0010: 75 72 65 20 20 6e 73 72   ure  nsr
0018: 65 78 65 63 64 2e 65 78   execd.ex
0020: 65 20 37 2e 36 2e 31 2e   e 7.6.1.
0028: 30 20 69 6e 20 6c 69 62   0 in lib
0030: 72 70 63 2e 64 6c 6c 20   rpc.dll
0038: 37 2e 36 2e 31 2e 30 20   7.6.1.0
0040: 61 74 20 6f 66 66 73 65   at offse
0048: 74 20 30 30 30 30 33 34   t 000034
0050: 35 34                     54     

Could you please help me ?

Kind regards

Pascal