如果某條邊與浮動方向同向，則向該邊上的浮動框應用邊距時，邊距會增加一倍。此錯誤只影響一次或多次浮動的某行中的第一次浮動。

影響: Internet Explorer 6.0

該錯誤只影響ie而不影響其他瀏覽器，我們可以考慮用hack來解決�。�！

_display:inline;

加入上面這句問題解決

adobe官方解決方法：

Problem
When a margin is applied to a floated box on the same side as the direction the box is floated AND the floated box is the first one inside its containing box, the margin is doubled. (In other words, a left-floated box with margin-left set to move it away from its containing box will be twice as far away from the left edge of the containing box as intended.)

Solution
Specify display: inline; for the affected float.

Detailed description
This bug only reproduces when the floated element''s margin extends in the same direction as the float itself, and is between the float and the container box''s inside edge. Subsequent floats with similar margins won''t reproduce this bug- just the first float in any row of floated elements.

原文地址：http://www.adobe.com/cfusion/communityengine/index.cfm?event=findByTextId&productid=1&textid=DOUBLED_FLOAT_MARGIN