KDE4 Problem ?

I experienced a problem with Kubuntu.

I couldn't login to the X window, and even manually starting the X window after logging in via console, sometimes doesn't work. Well, (un)fortunately, I'm not the only one experiencing this problem. Thanks to this link and it solves my problem: http://ubuntuforums.org/showthread.php?p=4320584

So if you think we have the same problem, open the file 'xsession-errors' at your home directory with any text editor (vi/vim/etc) or commands like tail,less,etc:

~$ tail -20 ~/.xsession-errors

And look at the end of the file for something similar below:
:
kdecore (KLocale): WARNING: Definition of PluralForm is none of NoPlural/TwoForms/French/OneTwoRest/Russian/Polish/ Slovenian/Lithuanian/Czech/Slovak/Arabic/Balcan/Ma cedonian/Gaeilge/Maltese: Definition of PluralForm - to be set by the translator of kdelibs.po
:

This is a language pack problem. So removing the following will fix the problem (atleast for me).

~$ sudo aptitude remove language-pack-kde-en
~$ sudo aptitude remove language-pack-kde-en-base

Some Linux shortcuts

While some of them are very common, you might still learn some, as I do.

# / - root directory
# ./ - current directory
# ./command_name - run a command in the current directory when the
current directory is not on the path
# ../ - parent directory
# ~ - home directory
# $ - typical prompt when logged in as ordinary user
# # - typical prompt when logged in as root or superuser
# ! - repeat specified command
# !! - repeat previous command
# ^^ - repeat previous command with substitution
# & - run a program in background mode
# [Tab][Tab] - prints a list of all available commands. This is just an
example of autocomplete with no restriction on the first letter.

# x[Tab][Tab] - prints a list of all available completions for a
command, where the beginning is "x''

# [Alt][Ctrl][F1] - switch to the first virtual text console

# [Alt][Ctrl][Fn] - switch to the nth virtual text console. Typically,
there are six on a Linux PC system.

# [Alt][Ctrl][F7] - switch to the first GUI console, if there is one
running. If the graphical console freezes, one can switch to a
nongraphical console, kill the process that is giving problems, and
switch back to the graphical console using this shortcut.

# [ArrowUp] - scroll through the command history (in bash)

# [Shift][PageUp] - scroll terminal output up. This also works at the
login prompt, so you can scroll through your boot messages.

# [Shift][PageDown] - scroll terminal output down

# [Ctrl][Alt][+] - switch to next X server resolution (if the server is
set up for more than one resolution)

# [Ctrl][Alt][-] - change to previous X server resolution

# [Ctrl][Alt][BkSpc] - kill the current X server. Used when normal exit
is not possible.

# [Ctrl][Alt][Del] - shut down the system and reboot

# [Ctrl]c - kill the current process

# [Ctrl]d - logout from the current terminal

# [Ctrl]s - stop transfer to current terminal

# [Ctrl]q - resume transfer to current terminal. This should be tried if
the terminal stops responding.

# [Ctrl]z - send current process to the background

# reset - restore a terminal to its default settings

# [Leftmousebutton] - Hold down left mouse button and drag to highlight
text. Releasing the button copies the region to the text buffer under X
and (if gpm is installed) in console mode.

# [Middlemousebutton] - Copies text from the text buffer and inserts it
at the cursor location. With a two-button mouse, click on both buttons
simultaneously. It is necessary for three-button emulation to be
enabled, either under gpm or in XF86Config.
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