Tortoise for Subversion restarts Windows Explorer

Hi guys

I have a subversion server installed on my Windows Vista Home Premium.
To access the repository, I use Tortoise for Subversion. When I get files
from the repository, my Windows Explorer restarts.

This may have to do something with the Windows Defender(copied from the
System event log):

Windows Defender Real-Time Protection agent has detected changes. Microsoft
recommends you analyze the software that made these changes for potential
risks. You can use information about how these programs operate to choose
whether to allow them to run or remove them from your computer. Allow
changes only if you trust the program or the software publisher. Windows
Defender can't undo changes that you allow.
For more information please see the following:
Not Applicable
Scan ID: {68AE3FE1-6CE5-426D-809D-6E10E1A39B57}
User: Remo-PC\Remo
Name: Unknown
ID:
Severity ID:
Category ID:
Path Found:
clsid:HKLM\SOFTWARE\CLASSES\CLSID\{30351349-7B7D-4FCC-81B4-1E394CA267EB};regkey:HKLM\SOFTWARE\CLASSES\CLSID\{ 30351349-7B7D-4FCC-81B4-1E394CA267EB};regkey:HKLM\Software\Classes\*\shell ex\ContextMenuHandlers\TortoiseSVN;contextmenu:HKL M\Software\Classes\*\shellex\ContextMenuHandlers\T ortoiseSVN;file:C:\Program
Files\TortoiseSVN\bin\tortoisesvn.dll
Alert Type: Unclassified software
Detection Type:


How to so,ve that problem?

Thanks