I am maintaining a site that is umbraco v 4.0.4.2.
The site is at the root (not a virtual directory)

Sometimes when I add an image to a page (either using the image picker, or pasting the img html directly into the html), after I save, then it redraws the page in the umbraco editor, a completely different image will show up.  It will still have the original alt tag and size info, just the completely wrong image path.

At first I thought it was saving wrong, but whe I saved/published and then viewed the page, the correct image was there.  I can look at the cmsContentXml table and see that the correct image is saved the first time.  The image path is valid as well.  It seems that when the content gets loaded into the editor, the img src value is changed. 

As far as I can tell, it only happens to images in a certain folder & it's subfolders. (but the they have a LOT of images and pages so haven't tested every one).  And the image it changes to will be the same for each subfolder (ie all images in subfolder X get changed to image Y)

So, anyone know any reason why that would happen?  Why would the image path be changed upon loading into the editor?  Anyone have any ideas how to fix this?

The client would like it fixed, vs just setting up a new folder and re-uploading the images. (which I tried, and worked, the new uploaded image in a new folder works, but they dont' want to have to reupload all those images and then go change all the pages)

(ps, upgrading version is not an option)