Hi,
I am also experiencing the same problem as valerietherese. I installed a new theme (Fauna) and used its custom header upload feature. Whilst uploading there was a message saying that the upload has failed. When I went back to the Presentation page, this message came up as well.
Which files should I re-upload? I tried creating a /wp-content/uploads/2007/07 folder to put in the image but it still did not work.
Thanks in advance for any help.