Low screen resolution on login after boot

Hello,

I have:

• Mac OS X 10.10.1 Yosemite
• MacBook Pro (Retina, 15-inch, Late 2013)
• Processor 2,3 GHz Intel Core i7
• Memory 16 GB 1600 MHz DDR3
• Graphics NVIDIA GeForce GT 750M 2048 MB and Intel Iris Pro Graphics 5200
• Wacom Intuos Pen & Touch CTH-480/S
• I'm using Adobe Photoshop CC 2014.2.1.
• I don't have any external monitors

I'm using:

• FileVault on
• Display resolution, Scaled, More Space

I have done:

• PRAM reset: http://support.apple.com/kb/PH14222?viewlocale=en_US
• SMC reset: http://support.apple.com/en-us/HT201295
• MacOS Yosemite reinstall (without formating)

The problem I have:

• The screen resolution at the login screen is lower than the screen resolution I had set to the desktop.
• Every time I restart my computer and login to the computer, I have a screen shuttering of the wallpaper and also the Wacom tablet has issues regarding the mapping area because, looks like the Wacom tablet takes the screen resolution of the login screen.
• More detail regarding the Wacom tablet issue: Wacom, issue with mapping area

Some screenshots from the Wacom tablet mapping issue:

So my questions will be:

• Does anyone else has this Wacom mapping area issue?
• Does the login screen resolution should match the desktop resolution?
• Is there any way to set a screen resolution to the login screen?
• Is there any way to set a screen resolution for all the users at the same time? Like setting a default setting?
• Do I have any hardware issue?
• Does the "wallpaper shutter" something normal?

Thank you all for any comments or suggestions.

Regards.