Not quite sure I I get you. You say at the end that all other favicons work. Is it just yours which doesn;t? and where yours doesn't are you referring only to the mac Safari?
Anyhoo, All I could suggest is to make sure that the favicon link, is in the head of your document. and that you have the favicon uploaded to your server.
<link rel="shortcut icon" href="/images/favicon.ico" >
making sure that the location of your favicon is as shown in the link.