screen getting stuck on startup

Hi all,

I'm facing the following strange problem with screen.

My .xinitrc / .xsession has the following line:

(/usr/bin/xterm -geometry 80x46+1440-0 -T 2.1 -n 2.1 -e screen -m &)

*Sometimes*, when I log in to an X session, the xterm started above 
is blank, with only a "[" (black fg, red bg) in the first position (upper
left-hand corner). In this condition, no commands seem to work.

Once the Xsession is up and running, I can type the above command at
a prompt, and xterm comes up with screen running just fine. Its appearance
is roughly:

---------
hostname$ 
...
...
<hardstatus line>
---------

I have the following lines in my .screenrc:

hardstatus alwayslastline
hardstatus string '%{=kw}%-w%{= rk}[%n %t]%{-}%+w %=%{= kG}[%d/%m %c]'

I also have PS1="`hostname -s`$ " in my .bashrc.

I'd be much obliged if someone could please explain what this occasional
problem might be due to.

Thanks,
Mandar.