Prior to FileLocator Pro version 5.5 the shell extension could sometimes crash with VS 2008. Version 5.5 removed all links to MFC in the shell extension.
More information here:
FIX: The Explorer.exe file crashes when you open a Shell extension that is written by using MFC
http://support.microsoft.com/kb/958314/en-us
Copied from the web site:
SymptomsWhen you use Windows Explorer or Internet Explorer to open a Shell extension that was created by using Microsoft Foundation Class (MFC) on a computer that has Microsoft Visual Studio 2008 Service Pack 1 (SP1) or Visual C++ 2008 Feature Pack installed, you see "Not Responding" in the top left corner of Windows Explorer or of Internet Explorer. Eventually, the Explorer.exe file crashes.
CauseThis problem occurs because MFC calls the SHAppBarMessage API. Then, the SHAppBarMessage API calls the SendMessage method in the context of the MFC DllMain function in the Mfc90ud.dll file. Therefore, a deadlock occurs.