IE6 non-compliant behavior
When testing my own blog in Internet Explorer 6, I noticed that the text inside some posts was randomly disappearing. An example of what this looks like in IE6 is to the left. There can be several reasons why this happens, but the main reason is that following a "floated" element, IE6 sometimes loses track of the width of elements that don't have a height specification, no matter what value it is.
A floated element is one, such as a DIV or SPAN, upon which a CSS rule specifying "float:left;", "float:right;", or "float:none;" has been applied. Hovering your mouse over such elements randomly causes them to reappear.
I primarily use Mozilla Firefox for surfing and development work because it is compliant with W3C valid CSS standards and has a host of cool and useful plugins, such as Firebug. Firebug has an inspection mode where you can reveal any page element's CSS or HTML code merely by just hovering over it. You can also "inject" CSS, HTML and script statements in real time or comment out existing CSS rules to immediately see how the content is affected by such changes (my favorite). » More...
