A website which has been designed carefully should work on all major W3c compatible browsers like Firefox, Chrome, Safari, Opera. However more or less it should look the same in IE 8 with slight changes. If your website is not working properly in IE 8 it might be because of two reasons.
1. IE 8 gets into compatibility mode.
2. Your CSS is not designed properly.
IE8 may also behave as IE7. Sometimes when someone viewing your website in IE8 mode clicks the compatibility button it automatically goes into IE7 mode. IE8 will also get into compatibility mode if the browser automatically decides that your website is best viewed in IE7.
But you should see to it that this auto compatibility mode switching never happens and there is a way to tell IE8 to stop all this auto switching, by adding a small META tag to the necessary web page. When IE8 views this META tag it automatically ignores the compatibility view and always tries to display the page in it’s most standard mode.
<meta http-equiv="X-UA-Compatible" content="IE=edge" /
Put the above META tag in your HTML page’s <HEAD> section below the <TITLE> tag. This tag will be compatible with future versions of IE also.
You can check for any errors in your CSS using the W3C’S online validator (validator.w3.org). If you are using Firefox there is a plug-in available for download with which you can validate your CSS(chrispederick.com/work/web-developer/). A similiar tool is available for all those who are using Apple’s Safari browser. You can download the tool from (zappatic.net/projects/safarivalidator)