GDM on FreeBSD 5.2

[James]

When starting GDM on 5.2 X just crashes.   After the first crash it
comes back with a blank dialog box (and a red - icon) with one button.  
After clicking that button, X exits again.

This is the last (and only) fatal error reported in the log file:

xf86OpenConsole: VT_SETMODE VT_PROCESS failed



I am using nvidia display drivers.   X works fine otherwise (startx and
xdm).


Any ideas?

Thanks,
James