Can't open XFree86 log file

[Russell <rjshaw@iprimus.com.au>]

Hi all,

As root, i can start XFree86 and it works ok. However, as a
normal user, i get an error:
  Fatal server error:
    Cannot open log file "/var/log/XFree86.0.log"

I've tried deleting it. What else can i try?