>>> $ sux -
>>> > (enter root password)
>>> > # synaptic
>>> >
>>> > DOES WORK.

But synaptic is gtk. If anyone got a Trinity app running as root with 
sux I would really like to know. (I don't/won't use sudo, it's disabled)

I read, can't remember where, it's better to put this in your ~/bashrc 
than use xhost + :

#maybe this fixes x for root
export XAUTHORITY=$HOME/.Xauthority

It works for non-trinity (gtk)