I know this has been discussed before, but I am disperate. I tried everything and I am close to work but I really really need some help. So I did exactly what Simon said in a separate discussiopn (thanks a lot, Simon!) and I manage to see the Add item in the K2 login module (also in the category list). But when I press Add Item (or Edit item for an existing article) it show just an empty page, expect for 10-20 pixels on the left side where I can see the previous page. So it looks like a "pop-up window" is displayed but in my case that window is empty. Any idea what might be wrong here?Thanks for such a great component and I will really apreciate your help on this.

Which browzer are you using?
Can you send a link to the offending page?

I tried both Firefox and Explorer.
You can go to www.reignoftennis.com/joomla and connect as costin/costin123. Then try to add an article.

Thanks.