3.8.1 Upgrade Issue? Registration E-Mails

[kensandell]

We have upgraded from 3.8.0 to 3.8.1.
New Users get their registration e-mail - but the headers are messed up a bit.

The from ADDRESS is correct, but the name is simply _
Does anyone know how to fix this?

New Post messages, Private Message e-mails, etc...all work properly...

[Marco van Herwaarden]

To troubleshoot this, please remove any hacks and disable your plugins, then see if you still have this problem.
Note: To temporarily disable the plugin system, edit config.php and add this line right under <?php

define('DISABLE_HOOKS', true);

If so, reupload all the original vB non-image files (except install.php). Make sure you upload these in ASCII format and overwrite the ones on the server.