It's been ages since I used FrontPage hover buttons but if memory serves you may have to install a recent Java Runtime into your web browser to view them.
FrontPage hover buttons are actually tiny Java applications. Java has been an important part of the web browser world for ages now, but all browsers interact with Java differently and some of them are better than others at certain things. Older versions of Netscape would crash quite badly when viewing FrontPage hover buttons.
And again, if memory serves, the FrontPage hover buttons used to rely on FrontPage Server Extensions on your web server to work correctly. I'm going way, way back here, into the dim and distant reaches of my murky past (FrontPage 98) but you may have to publish the page to get things working properly.
Hover buttons require that the file be saved and viewed in a web browser to work. You should also be advised that FrontPage hover buttons will not display for computers with Windows XP SP2 installed. Instead, there will be no link at all with the following browser message:
"To help protect your security, Internet Explorer has restricted this file from showing active content that could access your computer. Click here for options..."
It might help to know your version of Windows and FrontPage.
I'll be in front of several computers in the morning with various versions of FrontPage installed, so if nobody manages to solve this one for you I'll look back in on it again over the weekend.