IE7 Quirks

Max over at OpenLaszlo was writing about some browser/quirk detection that he put together for v4.0. He listed in his post a number of quirks for IE7, some of which I was aware of, and some I wasn’t.

• Can’t set opacity on any div that contains <input type="text"/> or <textarea/> without getting nasty visual artifacts in the text field.
• Must use the AlphaImageLoader if we want opacity to apply to a div and all its children.
• AlphaimageLoader must have its src property set to the URL of an image to prevent a red x/missing image icon from appearing
• AlphaimageLoader does not send onload/error events – instead we have to use the img tag mentioned above
• IE 7 still has memory leaks for apps loaded in iframes
• Empty divs with style.backgroundColor set appear ~10px tall unless they contain an img (for less than 2px tall) or have style.fontSize = '0px' applied.
• IE does not support ' when setting a div’s innerHTML property
• IE does not send onclick/onmouse* events for divs without a blank image attached

One of my favorite IE7 quirks has to do with z-index being overrided by the order in which the element appears in the DOM. If a div has a z-index of any positive number and it’s followed by a div with a z-index of anything less, and they are positioned in an overlapping manor, the div that comes second in the DOM appears in front of the div with the higher z-index value.

What are some of your "favorite" IE7 bugs / quirks? I’d like to put together a comprehensive list.