Spry Submenus Not Visible on RHS only

My spry submenus work totally fine except for the very far right hand side of
the page where the submenus are cut off. I can see the very beginning of the
submenu but the rest of it with the text is hidden once it goes past the edge
of the page. Clicking on the small part which is visible works, but users
still need to see the entire submenu. This is a problem only in Firefox
(3.0.7) and Safari (3.1.2). IE7 works fine where the submenus on the RHS are
clearly visible as I hover and they extend past the right hand edge of the
page. Thanks for any input.