My float breaks on ONE person’s Firefox (v.12) on a Windows machine (that I’m aware of)… Same version of Firefox on Windows displays fine on other machines.
Simplified breakdown of layout: Two container divs containing two floated fixed-width divs:
<div id="frame" style="width:942px; display:block"> <!--extra 2 px to accommodate border on interior div -->
<div id="frame_content" style="width:940px; border: 1px solid; display: block">
<div id="column_left" style="width:626px;float:left;"></div>
<div id="column_right" style="width:314px;float:right;"></div> <!-- combined width of floated divs = 940 -->
</div>
</div>
Adjusting the width of column_right to 313px fixes, but there is a 1px gap between the columns.
At my wit’s end – because it’s just the one computer! Any ideas??
Is the zoom level different on each machine? I’ve seen something similar myself where a floated element was wrapping onto a new line at certain zoom levels. Try pressing ctrl 0 on the affected machine to reset zoom to 100%