CS5 issue with external AS2 classes?

I recently took over an all-Flash site that I didn't design. Almost every .fla makes calls to external AS2 classes including the Robert Penner classes among others. Like this:

import com.gs.*;
import com.robertpenner.easing.*;
import com.vandalEyes.utils.*;

I have the class files in my client's folder but when I go to render the movie, I get no errors and a blank screen so no movie. Turns out after running the .swf through a decompiler, it never saw or loaded the classes. I did some Googling on the subject and supposedly starting with CS4, Flash doesn't load external AS2 classes anymore. Is that so? Or just bunk? And if it isn't, how can I get it to load these class files into my movie?