lucy24 - 6:32 pm on Jul 9, 2013 (gmt 0)
I seriously doubt it's because the search engine can't see your meta description. More likely it doesn't, ahem, like the meta description and thinks it can do better on its own. When you consider that The World's Leading Search Engine routinely makes up whole new titles for a page, changing the description is pretty minor.
You might even consider it a good thing: different search engines show different information. If they were all identical there wouldn't be much point would there.