Any side margins (the blue 100px) applied to block-level hasLayout elements will be erroneously inherited (the red 100px) by text, submit, button and textarea fields contained within the block elements. Select boxes, checkboxes & radio buttons are not affected.

Applying margin: 0 to the input or textarea fields has no effect. All your margin are belong to us.

Here is my test page »

If your design does not have a border on the block-level element, this bug has the identical visual effect as the well-known IE6 floated element/margin-doubling bug, but the real cause is not the IE6 margin-doubling bug.

I found this issue having just installed IE7, still giddy over the wide array of css fixes. For a few minutes, I thought maybe the IE team had forgotten to fix the float/margin-doubling bug with blockified labels, but no.. this margin inheritance bug is an entirely different beast.

My findings are a little different from the other information I found (at the time of this post, the only existing explanation of this bug I could find was from Paul van Steenoven):

• it does not matter if the elements are contained in a fieldset
• input type=”checkbox” and type=”radio” are not affected

The fix / hack

• wrap your bug-affected input / textarea elements in any inline element, like a span (if you’re okay with that .. I’m not)

Or, if possible:

• set display: inline on the block-level hasLayout parent element, or similarly, remove the css property that’s triggering hasLayout (width, etc) on the block-level parent element (not possible in most cases)
• remove side margins on all parent containers of the form element (suggested by Barry Jaspan, who points out this solution also may not be realistic)
• set an IE-only negative margin on the affected form elements (also from Barry, who agrees with you this is needlessly messy, to the point where CSS purists may start throwing heavy objects)
• include text on the same line just before the form element (yep, Barry again, nice catch. Not possible if you want the text above the form element.. for example, some text<br /> <input .. /> doesn’t work)
• any others?

Other sites with information on this bug

• Paul van Steenoven’s test page
  
• the test page, expanded to show situations where Paul’s overflow: hidden fix does not work
• quirksmode report

Update:

• Barry Jaspan did a nice writeup, which was later covered by positioniseverything. I’m rather bitter, since I did my writeup about the bug about a month prior. Granted, Barry covered the issue more in-depth, and he also points out that the affected form elements actually inherit the sum of the side-margins of all parent elements, AND provided several more methods to work around the bug.

In setting up the new vehicle details page for DDC, I noticed that the background color for the 24-bit PNGs did not match the css background color, but only in IE6.

Searching online, I found this is a known bug with IE that stems from a flawed interpretation of the PNG’s gAMA setting. It’s fantastic that the IE team added PNG alpha transparency to IE7, but apparently they kept the gAMA bug in IE7 to make sure browser compatibility specialists keep their jobs for years to come.

In short, the fix is to remove the gAMA chunk using a tool such as TweakPNG or Pngcrush — I used TweakPNG (freeware, super easy to use, no installer) which worked great for fixing one image at a time. Fun stuff.