Topic: HTML Text In Footer Not Visible On Macs

I have uploaded my site containing the HTML embedded SimpleViewer Pro to my web server and it all works great - if you are using a PC.  However, all the people I know using Macs tell me there are no visible links in the footer whatsoever - and in fact there are several.  They are visible and they all work perfectly on PC's. In fact one Mac user told me the footer appears as a thick white bar (it's light black), no doubt the 20 px width of the footer.  The Mac users are using Safari and/or Firefox browsers and it appears the same in both browsers.  I have no idea what is causing this on Macs.  Has anyone else had similar experiences.  Of note ... In order for the Mac users to get beyond the welcome page I added a link to the Header section for the home page and it is visible and works on both Mac's and PC.