A recent comment posted in a response to an enigma question mentioned information on how to post images in the response. This particular response mentioned that only .jpeg images seemed to be allowed. I was pretty sure that .gif images were also allowed, so I went and checked the source code just to be sure. The actual allowed image formats according to the source code is: jpg, jpeg, gif, png. So at work, using Firefox browser, I posted a response to this, and included a .gif image in the response. I was able to see this image and so presumed that all was working as expected.
When I returned home and viewed the page from my own computer, I saw that the image I posted before was not being displayed, and instead an image about not hotlinking was displayed. No problem, I found another .gif image on the internet, and edited my response to include the new image. I previewed the response and all displayed ok, so I posted it. It was then I saw that the image was not being displayed.
3 or 4 hours later, I believed I had found a fix for it which was adding a blank url attribute to the body tag into the style sheet for the site. The image then displayed on the page and I thought it was all done. Unfortunately not. I went to a different enigma question page and added an image into a response, and previewed it. The image would not display.
I then removed all the background image urls from the stylesheet and the image then displayed. I also noticed that if somebody had already posted some images in a response which were displaying ok, if I edited the page and added an image above that response, then the image in the response would not display. It seemed as though the second image that appeared on the page would not display, but the first and any others after the second image would. This is the strangest bug I have ever seen regarding web browser rendering. Anyway, I put the style sheet back to how it was, and tried to do some more searching on the net. I came across a post mentioning Adblock Plus. I have this installed as an addon for Firefox, however, according to it, it says it was blocking zero items on my page, plus Firebug was showing no problems at all with the request and the response for the image that was not showing. I disabled Adblock Plus for my domain, and refreshed the page. The image now displayed, I refreshed lots more times just to make sure, and every time it displayed. I went to a few more enigma questions and previewed adding a repsonse with an image, and it all seemed to display correctly.
The browser I was using was the latest version of Firefox on the 3.0 series, which I think was 3.013. I downloaded Firefox 3.5 and installed that, and then tested again, with Adblock Plus enabled again. Images are displaying. I am still a bit worried that the underlying issue may still exist, and that some time in the future, I'm going to try and post an image, and it's not going to display. My concern is based on the fact that the problem disappeared when removing background images from the stylesheet, or even disabling all styles on the page.
I may start looking into getting a new design for the site, which will use a new stylesheet, as I am convinced that the issue is related somehow to the style sheet. However, for now, if images are not displaying, it appears upgrading to the latest version of Firefox should fix it.
If anyone experiences the issue of an image not displaying, please let me know. Information on the browser you use, what page you were trying to post on and the URL of the image would be very helpful. I can't promise that I'll be able to fix it though.