CMS Problem with trying to get an image in an article
 

In this tutorial video Andrean is showing us how to create an article. First of all, I'd like to note that you have to use the wysiwyg editor or else you won't get to see the "upload an image from the computer" window (1:00).

Anyway, I figured it out myself and switched my editor to wysiwyg. Now, when I try to upload an image I get an error:

Code:
[SecurityErrorEventType="SecurityError" bubbles=false cancelable=false eventPhase=2 text="Error #2049"]
When I use the other option and paste a url, I get yet another error:

Code:
Upload failed due to failure writing temporary file.
What's more, the first time, before switching to wysiwyg, I did manage to place an image in the article using the [ΙΜG] tag. Later, with wysiwyg and the image visible now, I tried to open the "image settings" window like shown in the video (1:18). I clicked on the image, I right-clicked, but nothing happened.

Does anybody know anything about all this?

thanx