We are now developing a website with drupal for a client. As the website is quite complex and we need handle many CSS files for modules and themes. Today I suddenly found that there are some CSS statements cannot work at IE. I have spent some time on that and finally we found IE cannot load some CSS files we add at the last in .info files. I guess IE has the limitation on the numbe rof CSS files load. But I don't believe in it because this is a tooooooooooo stupid reason....

After I had found same conclusion from others. I admit that I have put too many hopeness on IE.

In our case, we have 30 CSS files loaded in IE.

reference:
http://www.redfinsolutions.com/redfin-blog/ie-7-and-ie-8-impose-31-css-file-limit-drupal-beware