I did a search and didnt find what I was looking for.

When I try to open an attachment from Yahoo Mail I get a '404 Not Found' message. I went to the Apple store with no help from them. They couldnt figure it out. I tried opening the attachments from my Yahoo Mail on a PC and two other Macs and they all worked. Is this something to do with my Mac or Safari? Or is this a Yahoo server problem? If so, why would they open on the other Macs and PC?

PLEASE HELP! This is a computer I use often and the one I take on business.

Thanks in advance!