[Lynne]

I'd suggest looking into this issue using firebug > console. Right off the bat I am seeing errors on your pages like:

"NetworkError: 404 Not Found - http://arabic.rt.com/media/pics//168/"

So, it looks like you have entered some paths incorrectly. I'd check your error_logs to see if there is anything in there about the css.

I ran your page through a validator and it does not like these (they are incorrect html, I'd suggest you read up on them and correct it):
<!------------------------------------->

It also doesn't like your marquee tag since that is deprecated. I'd suggest correcting that also.

You are also missing the </p> tag that should be paired with this:

<td width="100%">
<p align="center" dir="rtl"><span style="font-size: 8pt; font-weight: 700">في حال وجود أي مواضيع او ردود مُخالفة من قبل
الأعضاء ، يرجى الإبلاغ عنها فورا باستخدام أيقونة

If any of the above errors are the cause of the issue, I would guess it was the last one.