latest upgrade breaks front-end authentication

Hello,

We have a site: keepthemflying.com that uses Mobile Joomla. If I do the latest upgrade (currently running 1.2.4, trying to upgrade to 1.2.5.1) then front-end authentication breaks. One can't log in and gets the message:

JAuthentication: :__construct: Could not load authentication libraries.
The only authentication plugin we're running is standard 'Authentication - Joomla'. I've restored the a site backup and have verified that it's the install of the update that breaks the authentication. Any help would be appreciated.

Brent Laminack

What Joomla version do you use?
Did you disabled auth plugins using MJ's extension manager ("Advanced" setting tab)?

that was it. somehow the joomla user auth was unchecked. all's well now.