I had the same problem, but figured it was an Epson problem. I called Epson and the tech didn't have to think twice about it and walked me through the fix. Unfortunately, I don't remember what it was...
but I definitely would stay away from formatting your hard drive, reinstalling the OS and Photoshop, at least until after you talk with Epson unsuccessfully.
In the meantime, a few things that I would suggest... (probably all of which you're doing, but it might be helpful to others reading this)
Open any image in Photoshop. In the print dialog, under Color Management, make sure you have "Photoshop Manages Colors" selected for Color Handling, and your Printer Profile should be the profile for your paper or canvas.
Click on Print Settings above the Color Management box to open the Print dialog window. In that window, make sure your 7900 printer is selected. "Presets" probably is "Default", but whatever it is leave that alone for the moment.
Further down in that window is "Page Setup" and that should be one of the role paper options or sheet paper. Below that is "Media Type" which I presume is where you have selected "Premium Luster Photo Paper (260)". Make sure the other options in that window are as you want them. Then... go back up to "Presets" and select "Save Current Settings as Preset" and name it something appropriate and save it. Then click "Save" at the bottom of the Print dialog window.
Close the image and shut down Photoshop. Open it again and see if the "Presets" setting has been retained. If not... call Epson.
P.S. In the Print dialog window where "Presets" is on the second line, open that drop-down menu and click on "Show Presets...". There will be a short delay, and another dialog window will open. At the bottom of that window is a checkbox "Reset Presets Menu to "Default Settings" After Printing". If it's selected, deselect it.