If you're just checking to see what's been changed, you'll at least need to upload the libs/ubbthreads.inc.php file as well, as that holds the current version #.
Thanks for this tip. I was able to successfully upgrade from 7.2b4 to 7.2b5 in less then 5 minutes by only loading the changed files.
To summarize for others, upload the full install directory AND libs/ubbthreads.inc.php. Then run [your url]/upgrade.php to find out exactly what needs to be uploaded.
Thanks again!