why is this site a certificate problem on my tablet only?

[PenguinLust]

When I goto http://www.eham.net/user/login in the native browser OR using Firefox I'm told there's a problem with the site's certificate. When I use a desktop FF (or any other desktop browser) this doesn't happen.
My tablet's system clock is current and automatic updates are set.

Posted via Android Central App

 

[jmagid51]

I have the same issue using the S5 or my Tab 3.0 de W1JMM