[Mediawiki-l] Image - different caption vs alt text

[Matt Gardner]

http://en.wikipedia.org/wiki/Wikipedia:Extended_image_syntax 
Thumbnail with caption text underneath that has one or more links
This option does not seem to work correctly on my page and works inconsistently on Wiki page.  Specifically, the image alt text does not display what is written as caption.
  a.. My page - Incorrect alt text, correct caption:
    a.. [[Image:Family.jpg|thumb|The Gardners' all gathered for [[2004-11|Thanksgiving 2004]]]]
    b.. Alt text: The Gardners' all gathered for 
    c.. Caption: The Gardners' all gathered for Thanksgiving 2004
  b.. Wiki - Correct hover, correct caption:
    a.. Tst.png (New syntax for images - definition of "thumbnail, thumb")
    b.. [[Image:tst.png|right|thumb|100px|This is a globe, and take a look at it in [[Media:tst.png|the actual size]]]]
    c.. Alt text: This is a globe, and take a look at it in the actual size
    d.. Caption: This is a globe, and take a look at it in the actual size
  c.. Wiki - Incorrect hover, correct caption:
    a.. Westminstpalace.jpg (Thumbnail with caption...)
    b.. [[Image:Westminstpalace.jpg|right|thumbnail|This is the [[Palace of Westminster]] in London]]
    c.. Alt text: This is the  in London
    d.. Caption: This is the Palace of Westminster in London
By the way, it might immediately appear as though the file extension (.jpg or .png) might be to blame, but I just added Family.png and it still does not work.  I also removed the caption from my code and left just the basic link, the alt text is still incorrect.

Suggestions?

Thanks.