Problems with xmaxima: "Failed to eval region"

Hi

I'm using xmaxima on ubuntu 8.04 and get the following message when I 
try to click some of the examples in the "Maxima Primer" (visible at 
start up):
"Failed to eval region
Failed to eval region
     while executing
"error [mc "Failed to eval region"]"
     (procedure "doInvoke" line 50)
     invoked from within
"doInvoke .browser.t1.text @253,81 "
     (command bound to event)"

After some time, this pops up:
"Starting maxima timed out, Wait longer?"

wxmaxima does not work either. For instance, if I write 1+1, wxmaxima 
returns;
"Not connected to maxima!"


Maxima CLI and imaxima (though emacs) works fine:
"xxx at xxx:~$ maxima

Maxima 5.13.0 http://maxima.sourceforge.net
Using Lisp GNU Common Lisp (GCL) GCL 2.6.8 (aka GCL)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
This is a development version of Maxima. The function bug_report()
provides bug reporting information.
(%i1) 1+1;
(%o1)                                  2
(%i2)
"

I've read a missing entry for localhost at /etc/hosts could be the 
problem, however, my /etc/hosts appears to be correct:
"xxx at xxx:~$ cat /etc/hosts
127.0.0.1 	localhost
127.0.1.1	thiscomputer

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts"


This is the specifications of my maxima install:
"xxx at xxx:~$ aptitude show  maxima
Package: maxima
State: installed
Automatically installed: yes
Version: 5.13.0-3ubuntu1
Priority: optional
Section: universe/math
Maintainer: Ubuntu MOTU Developers <ubuntu-motu at lists.ubuntu.com>
Uncompressed Size: 33,9M
Depends: gnuplot-nox, libc6 (>= 2.7-1), libgmp3c2, libice6 (>= 1:1.0.0), 
libncurses5 (>= 5.6+20071006-3), libreadline5 (>= 5.2), libsm6, 
libx11-6, libxaw7,
          libxext6, libxmu6, libxt6
Recommends: gv, maxima-share
Suggests: maxima-doc, texmacs, wish
Description: [...]"

BTW, I'm using wicd as my network manager as I had some problems with 
the default gnome network manager. I don't know if this is causing the 
problems.

Any help appreciated,
Lan Thuy Pham