This problem has been observed on Suse 9.2 and Fedora Core 3 and NX versions previous than 3.x.

If your application doesn't start, it's likely it's waiting for gconfd-2 to respond. It has been observed that it's very common for gconfd-2 to hang and not respond.

To verify if this is the case, please open a shell and try to kill the gconfd-2 process.

For example:

# killall -9 gconfd-2

Note that killing the process by a simple terminal signal doesn't seem to work.

Among the applications affected by this problem are Firefox, OpenOffice and most of the Gnome applications.