NOTE: The files attached in the above announcement had some incompatibility issues with a couple popular plugins, so a number of improvements have been made, as indicated here.

In your Admin if you're unexpectedly getting symbols like & converted into & then you probably need to apply the following updates.

These changes are applicable to v1.5.0-thru-v1.5.5a (you can right-click and save-as for each of these files):
a) /admin/includes/classes/AdminRequestSanitizer.php
b) /admin/includes/init_includes/init_sanitize.php
c) /admin/includes/auto_loaders/config.adminSanitize.php