Occasionally different anti-virus products can interfere with SharePoint operations. The following is a list of suggested locations to exclude from your AV scanner. Remember, this is merely a suggestion, so use at your own risk!
1. %PROGRAM FILES%\Common Files\Microsoft Shared\web server extensions\12 2. %WINNT%\temp 3. %PROGRAM FILES%\Microsoft Office Server 4. %WINNT%\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\ 5. Documents and Settings\All Users\Application Data\Microsoft\SharePoint\Config\ (the config cache) 6. %WINNT%\Temp\WebTempDir