Need help with odd problem

First time post since I've never had a problem like this before.
I have several websites hosted on the same server and all in subdirectories of the same main folder. Simple set up and its worked fine for a while now. Until now. Nearly all my sites use FCKeditor and have nearly identical setups. Two days ago I was editing text on one site and it prompted me to download fckeditor.html and took me to a file cannot be found page that was looking for the file in my temp folders. It still works perfectly on all my other sites but not this one. I changed the paths to go direct to other directories with working editors and still no go. I even moved the fckeditor folder to another spot in the site and pointed everything to that and no luck. Nothing was changed in the code for any of the pages of my site which is php and sql based. It simply stopped working and even after a fresh reinstall of fck it still does not work. I've cleared my cache and reinstalled. I've tested on firefox and IE with the same problem. Anyone have any idea why it would work on all my other sites and not this one?