Elgg 1.1 CSS Bug in Firefox, Javascript errors in IE

Hello everybody,

I setted up Elgg to use it with a site for an Educational Community, using Safari and all went well... but when I want to use it with IE6, 7 or 8 Beta it does not work due to javascript errors.

And using Firefox 3, it shows an error un the console that says:

Error: The stylesheet http://capacitarte.net/community/_css/css.css was not loaded because its MIME type, "text/html", is not "text/css".
Source File: http://capacitarte.net/community/
Line: 0

I've been looking all the source files, and all of them are phps... I cannot find any css to change that MIME. Of course I'm a newbie in this Elgg thing... and I don't know the platfform very well yet.

I´m using Goddady Free Hosting... and I suspect the banners are messing up the code, but I´m not shure... I will be able to buy Hosting when at least a prototype of the site has be done...

Elgg is so cool and I really want to use it for this and future projects... but Can anyone PLEASE give me a hand!?