internet explorer - RadGrid AJAX postback removes IE conditional comment -

I have Telerece Red Grade on my page. I have an IE7 specific stylesheet on my page wrapped in IE 7 conditional comments.

  & lt ;! - [If IE 7] & gt; & Lt; Link rel = "stylesheet" href = "/ css / ie7.css" /> & Lt; [Endif] - & gt;   
 When I click on a button in my RadGrid, for example, to sort a column, conditional comments are removed from the LINK tag and apply to the stylesheet page Which leads to layout problems.  
 Any idea is to click on a button in my Radheid, why the conditional comments of IE7 will be removed?  
 I teleic Web. Running the UI DLL version 2010.1.519.35.   
 
 
 After further research, the solution to my problem was the last shot on this page:  
 
 Take conditional comments from the head tag. This way they will not be updated by RadAjaxManager and will still apply based on the browser used. This is also valid XHTML 1.1 because HTML comment is omitted by the HTML validator ie    < / Html>