Black screen when loading game [SOLVED]

[samguili]

Hello,

After setting up Groovyarcade beta 2015 (unfortunately, i had usb issue with the stable release), i can't play any rom. Advmenu loads just fine but when i try any game, a black screen with a tiny white touch at the bottom will show up after a short loading.
I tried to run from terminal "groovymame rom" but it doesn't like it, saying me : "can't open display" 3 times and "segmentation fault core dumped" after. Screen problem it would seem...Something else : advmenu take its time to show up  : almost 1 minute, could it be linked ?

Asus a8v deluxe
Amd athlon 3500+
ati 9800 xt agp
2g ram
The screen is a small tv for test purposes.

thanks for your help !

EDIT : 1) i tried wahcade : the shortcut on lxde desktop doesn't work. The command "wahcade-setup" not found in the terminal. I tried sudo pacman -S wahcade with no luck and i dont want to go on compile and all... too hard.
2) tried attractmode : black screen with a white line quicly showing every 11s. I dont even know how to kill it to go back to gasetup...I will continue my investigations, any help appreciated
EDIT2 : I could finally install GroovyArcade-Arch2014.04.24-x86_64.iso without problem, and everything runs fine. I have now an issue with my usb joystick button encoder, like Harris.M https://code.google.com/p/groovyarcade/issues/detail?id=5. In GA 2015, i could use the joystick in lxde. It seems to be a kernel issue as reported in launchpad. I will try to install a new kernel to see if it helps. If i cant make it, i will start a new thread.