I'm trying to use the Astra library from Yahoo but I'm getting an error saying the base class BaseScrollPane is not found. It appears to be imported from fl.containers.BaseScrollPane, which leads me to believe it should be a part of the base flash 10 library and therefore should be available, but it appears to be missing. Is this part of a separate package from somewhere?

Update: For what it's worth, I found the actual class files in the Configuration/Component Source folder on my hard drive, but adding that to the class path (as well as the Components directory) did no good. I ended up fixing the issue by dragging a scroll pane component to the stage from the Components window and then deleting it, but I'm not sure what exactly that action changed that made it work, and would like to know for future reference.