Vista Tutorial - won.t search captions

I have been using the picture viewer that is
included with Vista. I really like it. It allows
me to add captions and tags easily. When I
search for images files using the file management
feature it only finds matches with words that I
used with tags. It does not seem to search captions.
According to a Microsoft article that I read,
It is supposed to search captions for matches as well

Here is the article.
http://windowshelp.microsoft.com/Win...d94451033.mspx

I am not able to get the search feature to work
with captions. No matter what word or phrase
that I add to the image caption, Vista search
can never find it. Yet it always finds matches
using tags. Microsoft says that it works for both.

Please help me to understand how to get it
to work right.

Thanks
Mike