I have created a patch to update 1 file. The patch deletes another file for no reason (that I can see). This is a 3rd party file delivered to \system32 by the original install. It has not been changed or updated in my source directory or in my .ism. It has exactly the same settings in my .ism as another file (which does not get deleted).
Out of exasperation, I deleted the Component for the 3rd party .dll from my patched .msi. And ran the Patch Wizard again. Low and behold, it leaves the file in place when I run the Update.exe. This seems like it is working exactly backwards. And why just for this one file? Any ideas?