Repro steps:

1. Create a webupdate installer. Deploy to a website.
2. Run the installer. Change the default installation directory; install to e.g. C:\test
3. Change the installer's version number and re-deploy.
4. Run wupdate.exe -or- manually download the new version of the installer .exe and run it

Actual results:

The update wants to install to the original default installation directory, downloading all new files and orphaning the version in the actual installation directory.

Expected results:

The update points to the actual installation directory.