suse9.2 update: xserver problems

hello, i updated from suse 9.0 to 9.2 lately. now i can not run programs using xserver if i change to root via su. the control-center does not work properly as well. i can not use things which require root rights. the button "sys-admin" (?german "systemverwalter") does not work anymore. i do: xhost +localhost su you . i get: Xlib: connection to ":0.0" refused by server. Xlib: No protocol specified. what went wrong? thanks for hints/urls/man/info ... Bernd -- https://gna.org/projects/mipisti - (microscope) picture stitching T_a_k_e__c_a_r_e__o_f__y_o_u_r__R_I_G_H_T_S. P_r_e_v_e_n_t__L_O_G_I_C--P_A_T_E_N_T_S http://www.ffii.org, http://www.nosoftwarepatents.org