Monitor turns off after apple screen

[Yoru]

This is a weird case, I have my hackitosh working flawlessly with 10.9 (booting without any flags), then I decided to give it to my parents, so put it with my parent's monitor, keyboard, mouse, etc... but after apple screen the monitor turns off.

This is my build:
- GA-EP45-DS3
- Core 2 Quad Q6600 G0
- 2x Kingston 2Gb DDR2 800
- Shappire HD 6870 1Gb
- OCZ ModXStream 900W
- 120Gb Sandisk Extreme SSD

My peripherals:
USB mouse and keyboard
1920x1200 DVI monitor (If I remember correctly DVI-D)

My parent's peripherals:
PS2 mouse and keyboard
1280x1024 VGA monitor with VGA to DVI-I adapter

My first thought was the screen resolution, but I have used Mode=1280x1024x32, GraphicsEnabler=No/Yes and -x bt nothing worked. Is it maybe the adapter? Any ideas?

 

[wildwillow]

Take a look here General Information on Display Preferences