BING and Yahoo show wrong meta description

Hi,

recently I use SEO by Yoast and I am very satisfied with this great plugin!

I also formulate my own meta description for each blog post.
My Problem: Have one of you ever seen that BING and Yahoo in the search results show the wrong meta description? I do not mean that they are do not show MY text and select their own text snippet from the blog post. They use MY correct meta description, but of the wrong blog post. For example: by the post about vinegar they show my meta description of the jam-cooking-blog-post. Or: for the article about vanilla tea they display the meta description of vegetables-blog-post. The meta description that appears changes every time I search, but they are always wrong. The same problem by the homepage.

This of course is really bad because the textsnippets should motivate users to click the link and visit the site! Google does always everything right and shows the correct meta description. I am confused.

Have you any idea what this might be?
Am I doing something wrong?
I am happy about any idea. Thank you!
orangepink

http://wordpress.org/extend/plugins/wordpress-seo/