Why do layers turned on in layer groups that are turned off flash when site opens?

I have layers within layer groups set up in the MXD (from before you could add folders to layer list), and I often will have one or more layers within the group turned on, so that when the group is turned on those layers will then turn on by default.  Unfortunately, in HTML5, these layers flash on when the site first opens, and then turn off.  Would be nice if this could be stopped.