no valid xml file and image paths won't work in another dire

I tried uploading the latest FCK and also CK to my Joomla 1.5 but got a message that there is no valid XML file.

Also, when this is resolved, another problem. I've had trouble with the site root url being prepended to my image paths, so they're something like siteroot/images/stories This is fine until I try downloading to my local server or moving to another directory. Then all the images disappear. I wish they could just use images/stories. tinyMCE does this so the paths always work, but it has few features I need.

UPDATE: Answered my own question. Got the Joomla FCK editor, and, lo, and behold, the latest security release had relative paths (that, or I hadn't noticed them in the previous config All I had to do was turn of warnings since a non-relevant one always comes up. No sense scaring users