Not sure where I should post this but I chose here.
I have been going absolutely crazy chasing disappearing graphics!
I've sponsor calling me and bitching that their graphic isn't appearing!
After much investigation and testing, over a 2 week period, I can tell you DO NOT put your graphics in a folder called "sponsor or sponsors". Also, don't include the word "banner" in your file names.
It seems that a certain Guardian of Spam and viruses, treat these condition as being potentially dangerous to those that choose to buy and run their software.
They replace the html code that displays the graphic with a remark field. "<-!" And they is no indication that they did it unless you look at the source code as displayed.
I found it by moving a graphic out of the folder "Sponsors" and than rename the file that had "banner" in it.
It could be happening and no one will know unless they are looking for the particular graphic.
Sorry to be long winded but I thought it would be worth it to prevent anyone from going through what I did.