IE 6.0.2900.2180.xpsp_sp2_gdr.050301-1519 shows ok both
http://commons.wikimedia.org/wiki/User:Joelmills/gallery and
http://72.14.203.104/search?sourceid=navclient-menuext&ie=UTF-8&q=cache%3Ahttp%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FUser%3AJoelmills%2Fgallery

-Check you can reproduce it (it's not due to a puntual server overload)

-Does it show if you see the original page (and not the google cache) ?

-Try to disable/uninstall the canon toolbar and/or the google one.

ayg wrote:

Works for me on IE 6.0.2900.2180.xpsp_sp2_gdr.050301-1519.

joelmills3 wrote:

FYI, I'm the person with the original problem. To answer the above questions:

It is reproducible - it is the same every time I look at the page.

I disabled the canon toolbar and uninstalled the google toolbar - did not help.

I have the exact same version of IE as Simetrical.

I'm not sure what you mean by the original page vs. the google cache.

fred_chessplayer wrote:

There was a different user, commons:User:Riggwelter, who had asked for my
assistance on this issue on my talk page on July 11. He said he had changed
various settings, but couldn't get it to work. He was using this version of IE,
and since Joel was using the same version I concluded (perhaps incorrectly) that
this was the problem.

To Joel: I notice that all images in your gallery are .JPG , as are the images
in [[Motala longwave]] that you said also didn't show up correctly. Does the
problem also occur on galleries with .jpg images?

joelmills3 wrote:

Yes, the problem also occurs in galleries with .jpg images (although like
with .JPG galleries some of the images are visible. Interestingly, galleries
with .png images appear fine.

Can it be some problem on the jpg-decoding of IE, only showing with the thumbs
of certain images? I guess they're always the same. Can you make a list of those
images? Do they fail even outside the gallery? And if you load only the image,
with no page?

joelmills3 wrote:

The images affected by this seem completely arbitrary, but the problem is
reproducible, i.e. if I make a new gallery the same images are invisible. They
also fail outside the gallery - any category containing them will not show the
image, although the link to that image will be OK.

To be clear - with the gallery, there is no image and no functioning link to the
image. With a category, there is no image but the link is functional. On the
image page everything is fine.

ayg wrote:

What about if you use the [[Image:Wiki.png|thumb|250px]] syntax to directly
include the image somewhere as a thumbnail?

joelmills3 wrote:

That works fine.

zelda069 wrote:

I have a user on french WP (username Polmars) who seems to have the same problem
on IE7 : somme images (always the same, apparently wide images, whose width is
bigger than height) are not displayed in galleries. This problem would have
appeared in 2006 (on french wikipedia).

See
http://fr.wikipedia.org/wiki/Image:Cat%C3%A9gorie-Image_de_Formule_1_%28images_manquantes%29_-_%282%29.PNG
for a sample screenshot of page
http://fr.wikipedia.org/wiki/Cat%C3%A9gorie:Image_de_Formule_1

I have so far not been able to reproduce his problem. If needed, I can ask him
further informations.

Closing as worksforme, since no one managed to reproduce it & could be be due to other factors out of mw control.

It was reported by several people. We could consider if it was fixed since. But the closing reason is wrong IMHO.