[wp-hackers] bypostauthor class disappears on comments page

[RePost]

I have .bypostauthor set to provide a tan background color to the 
author's comments. Seemed to be working, until it wasn't.

As you can see in this thread, the .bypostauthor class goes away 
sometime after about about noon today. I didn't make any changes to the 
stylesheet and I've tried disabling plugins, but can't pinpoint the 
cause. Same with the other comments page on this new blog.

http://bit.ly/fM0jhO

My styles for .bypostauthor:
ol.commentlist li.bypostauthor { background:#ebc094 !important; }
ol.commentlist li.comment ul.children li.bypostauthor { 
background:#ebc094 !important; }

I would appreciate any suggestions!

Thanks.