Installing many files to pre-existing folder is extremely slow

Installing many files to pre-existing folder is extremely slow
I found a 4+ year old thread that explained the same problem I'm having but I didn't want to necrobump it.

http://forums.winamp.com/showthread....hreadid=182845

I'm basically having the same problem as the thread at that URL using NSIS 2.37.

1. Install a very large set of files and folders using the normal File command.
2. Uninstall *most* of the files but *not all*. Leave a couple of folders with a couple of files on the disk (e.g., Web.config and other configuration files). In fact, I had to write my own .NET code that I call from the uninstaller that reads the Uninstall.dat file generated by AdvUninstLog. AdvUninstLog itself was far too slow for any large set of files and folders. I use AdvUninstLog to generate the Uninstall.dat file during install.
3. Run the same installer again and choose the same target folder.

Apparently whatever NSIS is doing when the screen displays "Searching in:" is not very efficient. This problem is causing the re-install to go from far less than a minute in length to 8-10 minutes in length.

Since the problem appears to be with NSIS itself and not any script I can debug or modify, I am at a loss as to how to tackle this problem.