Trouble running FlightGear

[edward]

Hi all,
I just installed FlightGear-0.9.9, edited /boot/loader.conf to adjust 
default and max data size limit to 1 GB.
When I launch the program by typing fgfs, I get a startup screen then 
the following and the program quits :
# fgfs
opening file: /usr/X11R6/share/FlightGear/Navaids/carrier_nav.dat
/usr/X11R6/share/FlightGear/Navaids/TACAN_freq.dat
X Error of failed request:  BadLength (poly request too large or 
internal Xlib length error)
   Major opcode of failed request:  144 (GLX)
   Minor opcode of failed request:  29 ()
   Serial number of failed request:  825
   Current serial number in output stream:  825
freeglut (fgfs): Failed to create cursor

Any idea what's going wrong ?
Thanks all,
Edward