firefox not showing vertical scrollbars in blog (See related posts)

hey everyone,

I'm new here and wondering if someone can help me out. i have a couple wordpress blogs i've built for clients, and i'm occasionally getting a wierd behavior in Firefox Win/Mac: sometimes even though there is plenty of content below the fold, no vertical scrollbar will show at all. it only does this on firefox.

here's an example (must view in firefox):

http://www.lorihedrickphotography.com/blog/

and i've tried adding this:


html {
height:101%;
overflow-y:scroll;
}


i looked at it with firebug, it validates. i'm stumped! any help would be greatly appreciated.

-jared