While upgrading from version 1.2.3 [3519] to version 1.2.3 [3673] I got this error:
I deleted zp-core and all files in main directory, uploaded new version, everything else is fine.

`
Zenphoto core files [Some files are missing or their filemtimes seem out of variance.]
Warning!

Perhaps there was a problem with the upload. You should check the following files:
.htaccess
zp-core/plugins/flv_playlist/playlist.php
zp-core/plugins/flv_playlist.php
`

This is not really a problem, just a bit of a co-ordination failure. Those two files are no longer part of the build, but the package list was not updated to reflect it. The current nightly has the correct package list.