You will be better off if you get away from using scenes as a general rule. They are problematic and shouldn't have survived time. It is possible that your menu code is not working well because of this. When you compile a file the scenes are merged into one timeline, so if you are using frame numbers as the basis for navigation that may be the problem.
You might want to check out the preloader tutorial(s) at www.gotoandlearn.com.
Spot on - took me a while to catch on to what you were saying (it being Friday and all), but it makes perfect sense. As one movie the frame reference was out by two frames because of the preloader so I just changed the frame target on each button accordingly. Interestingly, though, it wouldn't work if I built it as one scene with the preloader included (I even tried changing the export frame setting from 1 to 3 to allow for the preloader with no luck) - it would only work if I exported the whole thing as two scenes and allowed flash to merge the scenes.
I'm sure there's a more elegant way of doing it, but the movie works now and that makes me happy (as well as the client).
Thanks for your help.