Go to C:\Program Files\PythonSDK\Lib\site-packages and rename or remove the Camelot directory.  Then either install the other version of Camelot or add the source code to the PYTHONPATH environment variable.

When you see something like : ImportError: DLL load failed: The specified procedure could not be found. This probably means Windows tries to load the wrong DLL, possibly from another Python, PyQt or Qt installation.  Other installers tend to modify the PATH or other environment variables, which the Conceptive Python SDK does not (to allow running multiple versions next to each other).  Explicitly setting the PATH should prevent this behavior.

If this does not help, try the SET command on the command line to see what environment variables are set.