As long as the site you want to move is not using anything specific to Frontpage (Themes, forms, navigation, etc) then you should be fine to just FTP the files and be done with it.
You might also want to run it through the editor you are going to use to make sure everything still looks and functions the same. Another suggestion, try viewing your pages other than IE. Frontpage (and other such MS products) have a nasty habit of looking totally different in Mozilla/FireFox and others...
Hope everything works out well for ya!