Hi Greggory.
Sorry but I can also find out what I'm doing wrong on my side. I also had reinstalled the "Guest Additions" and replaced the gengradd.dlla and I can not make the 1600x900x32 resolution to appear as a screen resolution option.
But believe me Greggory, I really appreciate your help and online tutorial.
Just one last question. What did you put as Video Device when you installed the Virtual Machine? I will try a new fresh install in other virtual machine.
Thanks.
I installed using SNAP and then used the post-installation task program to change Video to Panorama. Then finally reset to GenGRADD and installed the extensions.
Make sure that you have the Video memory set to at least 7MB.