users and lyx

[robin]

Hello,
lyx run all right when I am as root, but when I am as user, when I am
wieving and 
saving a file I get error and :

"Font T 1/cmr/m/n/14.4=ecrm 1440 at 14.4 pt no loadable : Metric: (TFM)
file not
 found.
 /fontencoding/endcodingdefault/selectfont.
 Y wan't able to read the size data forthis font."
 
What must Ido to change for that lyx works fine with users ?

Thanks in advance for your help.
Gerard.