Just adding more information, I got the following error message when run the program from terminal using root

(Momentics:7775): GVFS-RemoteVolumeMonitor-WARNING **: cannot connect to the session bus: org.freedesktop.DBus.Error.
NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus 
security policy blocked the reply, the reply timeout expired, or the network connection was broken.

(Momentics:7775): GVFS-RemoteVolumeMonitor-WARNING **: cannot connect to the session bus: org.freedesktop.DBus.Error.
NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus 
security policy blocked the reply, the reply timeout expired, or the network connection was broken.

(Momentics:7775): GVFS-RemoteVolumeMonitor-WARNING **: cannot connect to the session bus: org.freedesktop.DBus.Error.
NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus 
security policy blocked the reply, the reply timeout expired, or the network connection was broken.
GConf Error: Failed to contact configuration server; some possible causes are that you need to enable TCP/IP networking 
for ORBit, or you have stale NFS locks due to a system crash. See http://projects.gnome.org/gconf/ for information. 
(Details -  1: Failed to get connection to session: Did not receive a reply. Possible causes include: the remote 
application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the 
network connection was broken.)

Do you have "SElinux" enabled? Any firewall rule blocking the IDE?

Fedora 11 was not a supported platform for Momentics 6.4.1 so we didn't test it. The upcoming Momentics 6.4.2 supports 
Fedora 11. You can download the experimental  version of IDE 4.7 here http://community.qnx.com/sf/frs/do/listReleases/
projects.ide/frs.ide_4_7

I'm new to QNX and have successifuly installed neutrino on Fedora (perhaps the same version as yours) and Momentics on 
XP SP2 and have run some of the IPC tutorial with the two. Now I'm trying to run Momentics on another clone Fedora 
system and got mixed results. 

When first installing I was asked to do it as root/su. So I figured a way to add a user to the Wheel group and was able 
to run Momentics as a su (super user) but had problems loading the "Welcome" tutorial screen. Consistenly got a bug 
doing that. At this junture I used run_qde.sh to start.

Than I tried to login as a user of the wheel group I tried to run it with the same run_qde.sh and didn't work, so a 
friend suggested I searched for another binary and I found qde one directory up from where run_qde.sh is placed, i.e. /
opt/qnx640 This time I got the following bug reported right off the bat:

System: Linux 2.6.27.15-170.2.24.fc10.i686 #1 SMP Wed Feb 11 23:58:12 EST 2009 i686
X Vendor: The X.Org Foundation
X Vendor Release: 10503000
Selinux: Enforcing
Accessibility: Disabled
GTK+ Theme: Nodoka
Icon Theme: Fedora

Memory status: size: 0 vsize: 0 resident: 0 share: 0 rss: 0 rss_rlim: 0
CPU usage: start_time: 0 rtime: 0 utime: 0 stime: 0 cutime:0 cstime: 0 timeout: 0 it_real_value: 0 frequency: 0



----------- .xsession-errors (802 sec old) ---------------------
error: The metadata does not have a thumbnail property
error: The metadata does not have a thumbnail property
error: The metadata does not have a thumbnail property
error: The metadata does not have a thumbnail property
error: The metadata does not have a thumbnail property
Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x3200083 ()
Window manager warning: meta_window_activate called by a pager with a 0 timestamp; the pager needs to be fixed.
Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x3c006e5 (Problems )
Window manager warning: meta_window_activate called by a pager with a 0 timestamp; the pager needs to be fixed.
Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x4200083 ()
Window manager warning: meta_window_activate called by a pager with a 0 timestamp; the pager needs to be fixed.
Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x42006ba (Problems )
Window manager warning: meta_window_activate called by a pager with a 0 timestamp; the pager needs to be fixed.
Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x3c0008f ()
Window manager warning: meta_window_activate called by a pager with a 0 timestamp; the pager needs to be fixed.
--------------------------------------------------

Did you also get these bugs? I guess I don't have a lot of help to give, but perhaps we have common shorcomings in our 
Fedora.