Breastplate Bug
 

Breastplate says that spell failure chance is 35%, but that's wrong, it is supposed to be 25%.

Additionally, Breastplate, when MITHRIL material is applied, does not reduce spell failure by 10%.

There's a stickied thread in the forum with a link to the bug reporting software. Posting bugs in the forum can easily get lost.

http://forums.wolflair.com/showthread.php?t=24976

Bugs should be reported through the bug reporting mechanism, I've copied the link here for you. As AndrewD2 pointed out, this is a stickies thread exclusively for dealing with bug reports.

It might take a couple days for someone to get back to you on this. If you've got screenshots of the bug, please wait until someone has contacted you to send them in.

Looks correct to me:
Attachment 2508

I also made a a Mithral set and again it looks correct:
Attachment 2509

Check if you are using the piecemeal armor variant rule. Mithril effects are only applied if all pieces of your suit are made of them.

Ahhhh good point. I always forget about the UC armor variant....