Like any user, I have problems using Linux. Typically it's a stupid default setting, like Suse not having X listen on the network, rearing it's ugly head. The solution, too, is typically some stupid one-liner. But your hair will fight a losing battle against your fists before you find out what stupid edit to make to which line. So I figured I might as well make it easier.
X server not listening to network on port 6000
Likely first to be noticed when you try to use the remote display abilities of X and you confirm that it isn't a firewall blocking access and that xhost allows access. If the command 'netstat -pantu | grep X' doesn't show a process named X listening on port 6000, this is what's wrong. I suppose I shouldn't call this setting 'stupid', because you shouldn't have unneeded services listening on your internet-facing connection. However, if you don't want men in the middle trying to connect it you'd firewall it off anyway, and if anyone gets far enough in to sniff my LAN traffic, the last thing I care about is if they sniff my remote-display game of Tetris.
The offending setting resides in /etc/sysconfig/displaymanager: DISPLAYMANAGER_XSERVER_TCP_PORT_6000_OPEN="no"
Find that line (cat displaymanager | grep -n TCP_PORT_6000), and change 'no' to 'yes', restart the desktop, and it's fixed!
lp: unable to print file: client-error-document-format-not-supported
If you've been spending hours fighting your cups server, I feel for you. If you've been slowly losing your sanity to inexplicable and astoundingly stupid behavoir, you're not alone. Perhaps it's solving one cryptic and unhelpful bug after another only to have to battle another for hours on end (Is my bitterness and hate showing)? With any luck, I can help put this one bastard of a problem to rest:
For whatever perverted reason, cups can't find it's mime.conv and mime.types files. Most likely these reside in /etc/cups/ or /etc. You need to make them accessible again:
Symlink known mime.conf and .types files to /etc/cups: ln -s /etc/cups/mime.conf [mime.conf file path]
Copy mime.conf and .types files into /etc/cups. You probably have conf and types files on your computer, most likely in /etc, and two copies of one file is a recipe for trouble.