After poking around all afternoon I think I have answered my own question. It appears that Mint has modified and uses their own version of Grub called Grub-gfxmint I believe. So the command splashimage is no longer recognized as valid and appears to be ignored. I have two choices here. Either live with the Mint boot screen, or apt-get remove the grub-gfxmint version and re-install the standard Grub package unless some learned guru reads this and can tell me how to use the new gfxmenu command to put up the splashimage I want.
Suggestions and comments welcome at this point.
"The Second Amendment isn't about protecting ourselves against criminals. It's about all of us protecting ourselves from all of you." ---Dr. Suzanne Gratia Hupp to Congressman Charles Schumer (D-NY)