In message <20011220173436.B153@solo.scraemondaemon.org>, "Ian P. Thomas Ipt" w
rites:
>	After having upgraded from Version 3.3.6 to 4.1.0, I can bring up
>blackbox and other programs like xbiff, xload, xman, etc. However, I can't
>bring up any xterm's or rxvt's.  When I try to, an rxvt will flash on the
>screen briefly and then disappear.  The error I've found examining a file
>created using the following
>
>startx >& xerrors
>
>	are as follows
>
>rxvt: couldn't open psuodo-tty
>rxvt:aborting
>
>	xterm doesn't present any error messages, it simply doesn't work.  I've
>tried entering X from xdm, and again, I'm still unable to get an xterm or
>rxvt.  Even the console app at the bottom of an xdm login screen appears
>briefly and then vanishes.
>	Not sure where to go next.
>

The obvious thing is to check the permissions on your master and slave 
ptys.  Here's what they look like on a (currently unused) pty on a 
1.5.2 system of mine running X 4.1:

crw-rw-rw-  1 root  wheel  6, 15 May 11  2001 /dev/ptypf
crw-rw-rw-  1 root  wheel  5, 15 May 11  2001 /dev/ttypf


		--Steve Bellovin, http://www.research.att.com/~smb
		Full text of "Firewalls" book now at http://www.wilyhacker.com