Usually, for IE6 to render rather correctly, all blocks on page should have hasLayout
enabled. I usually (somewhen about up to 2 years ago) achieved that by using height: 1px
either in personal IE6 stylesheet or with "star" hack:
/* hasLayout is now on in IE6 for elements having `example` class. */
* HTML .example {height: 1px; }
But IE6 does not deserve any efforts currently (I don't support it at all as of 2011 and recommend everyone to do the same).