Yes, this is the case. I regret having purchased my 19 upgrade. I was told by support that I needed to upgrade to 19 to be able to mount .Sd2f disk image. I went as far as to install a new system and a fresh copy of Toast 19. Still, after all this, I cannot mount any of my .Sd2f disk images. Adding to this, the support is unable to help (so far). They told me to create a new user at the operating system level and install 19 for that user. If an entire system install did not work, why on earth would creating a second user on my NEW system make a difference? I have zero faith that they can resolve this. I will edit this post if they do.