Strictly speaking, not the light CSS can make IE browser crash (crash)

Strictly speaking, not the light CSS can make IE browser crash (crash), but with a certain XHTML architecture. So far found that there are two types of code will make IE6, IE7 crash, as for the reason I tried to find the answer, but so far has not found ... If you have this knowledge or more detailed information I hope you can share it!

The code to crash the browser is as follows:
Crash IE6

<style type= "Text/css" >
A{position:relative;}
A:hover{float:left;}
</style>

<a href= "" > Crash IE6, Crash ie6</a>

When I write the page, I found that this bug only exists in IE6, and the application of a:active in the Pseudo class will also encounter this problem

Crash IE7

<style type= "Text/css" >
div{float:left;width:175px;}
Ul{overflow:hidden;white-space:nowrap;text-overflow:ellipsis;}
Li{position:relative;}
</style>

<div>
<ul>
<li> collapse collapse collapse collapse crash ie7</li>
<li> collapse collapse collapse collapse crash ie7</li>
</ul>
</div>

This bug was discovered by stealing rice, only in IE7. Stealing Rice said it is estimated that the processing of omitted words when crash off.