I have been cleaning up some issues with the Win64 port of Vim, including the Edit with Vim shell extension not working very well. When I built the shell extension with VS 2005 on x86, I would get the following whenever I right-clicked in Explorer:

Microsoft Visual C++ Runtime Library

Runtime Error!

Program: C:\WINDOWS\Explorer.EXE

R6034

An application has made an attempt to load the C runtime library incorrectly.
Please contact the application's support team for more information.

There was no mention of which ap­pli­ca­tion was at fault, though it was obvious in this case. I have also seen some mention of verclsid in the error dialog, though not when I took this snapshot.

The underlying problem relates to SxS, Fusion, and all that good stuff. By far the simplest fix was for me to statically link with libcmt.lib, instead of msvcrt.lib, rather than figure out the necessary manifest magic.