A: 

In firefox with the Web Developer Toolbar you can view broken images. In firefox the image would still be broken but you wont see anything like IE6 and IE7 show.

John Boker
A: 

Firefox and 'the other browsers' handle broken images more elegantly, but the image almost certainly is broken - they just aren't rendering it. Perhaps try to get in the habit of regularly checking your site logs for 404s, as it's not always obvious that you have a broken image in a contemporary browser.

Edit: Given your recent discovery, perhaps open the pngs in question in something like TweakPng - you may find that there are chunks causing this behaviour that you can safely remove. Compare the effected pngs with pngs that work properly and remove the offending chunks.

Bayard Randel
A: 

Note, that in xhtml (well, you closed the img tag) you should use " instead of '.

stanch
you're right. Since posting the question I've been going through the whole thing with a fine comb, I spotted the double quotes, but still no difference.
gargantaun
A: 

Hi, Could you please post the link to the site you refer in the Major Update? I'd like to grab the fix.

Thanks!

it's on my local machine at the moment, but the fix is here...http://labs.unitinteractive.com/unitpngfix.php
gargantaun
+4  A: 

You are missing the replacement gif.

All PNG fix methods require that a transparent gif be available to replace the png image, it's part of how the substitution works. If that gif is missing, then you get this broken image appearance even tho the PNG draws fine.

In the case of iepngfix.htc, it expects the file to be at /images/spacer.gif

ChiperSoft
A: 

If you are using iepngfix.htc you need to open it up and set the blank image path. The image needs to be a 1x1 .gif.

Looks like I was just barely beaten to the punch.

Ballsacian1
A: 

Yes, I had the same problem, and it was also with iepngfix.htc which allows transparency in IE6.

Yes, the required accompanying gif image was on the images folder, as instructed.

So I went into the htc file and entered the exact link and now everything works perfectly!

Martha
A: 

Thankyou chiperset.I am facing the same problem in my site cdnmobilesolutions.com. I have searched and read about 5 blog posts, answers to fix this issue. But not a single helped me to clearly understand what the problem is and how to fix it. After reading your post, I have uploaded that spacer image and it works. It solves the problem in just a minute for that I am worried from yesterday. I have tried to vote your post but it shows that you need 15 points to vote. Thanks once again.