Solving the problem in Live CD:
Insert live cd, and before the Ubuntu tries to boot into it press Esc repeatedly until you get to Ubuntu menu. Press F6 and select acpi=off and press enter. You can now press Esc again to close this sub-menu and press ‘Enter’ to boot into Live CD. This time your boot process should complete without any errors.

Solving the problem in installed system:
(Once you install Ubuntu using Live CD, you have to follow the following steps to fix this problem in your installation.)

1. In the grub menu, press ‘e’. Search for ‘quiet splash’ and add ‘acpi=off’ (without quotes) after that to make it look like ‘quiet splash acpi=off’. You’ll be able to boot in now.
2. Go to Applications->Accessories->Terminal
3. Execute:

   sudo gedit /etc/default/grub

4. Find the line which says GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash” and change it to the following:
   GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi=off”
5. Exit gedit.
6. Execute:

   sudo update-grub

7. Restart. This time you don’t have to edit anything. Ubuntu should boot without any issues.

Comments and suggestions are more than welcome.

dpkg: error processing /var/cache/apt/archives/wine1.2_1.2.3-0ubuntu1~ppa1_amd64.deb (–unpack):
wine1.2: 1.2.3-0ubuntu1~ppa1 (Multi-Arch: no) is not co-installable with wine1.2:i386 1.2.3-0ubuntu1~ppa1 (Multi-Arch: no) which is currently installed

You can’t simply remove 32bit wine using apt-get remove wine1.2. To fix the issue suffix the package name with ‘:i386’.

Therefore, I solved the problem by:

sudo dpkg -r wine1.2:i386

dpkg: error processing /var/cache/apt/archives/wine1.2_1.2.3-0ubuntu1~ppa1_amd64.deb (–unpack):
wine1.2: 1.2.3-0ubuntu1~ppa1 (Multi-Arch: no) is not co-installable with wine1.2:i386 1.2.3-0ubuntu1~ppa1 (Multi-Arch: no) which is currently installed

You can’t simply remove 32bit wine using apt-get remove wine1.2. To fix the issue suffix the package name with ‘:i386’.

Therefore, I solved the problem by:

sudo dpkg -r wine1.2:i386

I have i7 2630QM process which has 4 physical cores and 4 logical cores. I’ll show you how to make it act like a dual core machine instead.

Method 1:
This method is dynamic and doesn’t require a reboot. You can just open a terminal and try this out:

• sudo sh -c "echo 0 > /sys/devices/system/cpu7/online" sudo sh -c "echo 0 > /sys/devices/system/cpu6/online"

  Repeat the above steps for cpu2 to cpu7 and it’ll leave you with cpu0 and cpu1 active which is essentially what we’re trying to achieve.

Method 2:
This method will make the linux boot with 2 cores which might make kernel more optimized for dual core environment than the method above.

• Add maxcpus=2 to GRUB command line by doing the following:

  gksu gedit /etc/default/grub

  Find:

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

  and change it to

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash maxcpus=2"

• Then run:

  sudo update-grub

  When you reboot, linux will run on 2 cores.

After scavenging, what seemed like the whole WWW, I finally found a modified kernel by Kamal Mostafa which fixed the issue. You can see the bug reports and patch here.

The issue seemed to be with i915 kernel module and how it handled brightness on certain laptops which had different ACPI implementation.
Only install this kernel if you are using i915 kernel module. You can check if its active by executing:

lsmod | grep i915

If it gives you output, it means you’re using the i915 kernel module and you can proceed further. If it doesn’t give any output, you should leave this page.

Fix the brightness issue by installing kernel debs provided in Kamal’s PPA.

sudo add-apt-repository ppa:kamalmostafa/linux-kamal-mjgbacklight
sudo apt-get update
sudo apt-get dist-upgrade

This will install the modified kernel. Alternatively, you could do (not recommended):

sudo add-apt-repository ppa:kamalmostafa/linux-kamal-mjgbacklight
sudo apt-get update
sudo apt-get install linux-headers-2.6.38-10 linux-headers-2.6.38-10-generic linux-image-2.6.38-10-generic linux-libc-dev

Reboot into the modified kernel to confirm the brightness keys work. Cheers!

I have i7 2630QM process which has 4 physical cores and 4 logical cores. I’ll show you how to make it act like a dual core machine instead.

Method 1:
This method is dynamic and doesn’t require a reboot. You can just open a terminal and try this out:

• sudo sh -c "echo 0 > /sys/devices/system/cpu7/online" sudo sh -c "echo 0 > /sys/devices/system/cpu6/online"

  Repeat the above steps for cpu2 to cpu7 and it’ll leave you with cpu0 and cpu1 active which is essentially what we’re trying to achieve.

Method 2:
This method will make the linux boot with 2 cores which might make kernel more optimized for dual core environment than the method above.

• Add maxcpus=2 to GRUB command line by doing the following:

  gksu gedit /etc/default/grub

  Find:

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

  and change it to

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash maxcpus=2"

• Then run:

  sudo update-grub

  When you reboot, linux will run on 2 cores.

Uncaught Syntax error, unrecognized expression: [href=edit-comments.php?page=disqus]

It caused unmovable widgets, screen-options didn’t open and other related javascript issues in admin panel.

After some researching it turns out, there’s a simple fix.

In /wp-content/plugins/disqus-comment-system/disqus.php, find:

href=edit-comments.php?page=disqus

and replace it with:

href=”edit-comments.php?page=disqus”

Cheers

`menu_proxy_module_load': /usr/lib/virtualbox/VirtualBox: undefined symbol: menu_proxy_module_load
 
(<unknown>:23888): Gtk-WARNING **: Failed to load type module: (null)

This error was received while running Virtualbox. Though, it seems just a warning and doesn’t really change anything in the application, it does make the terminal messy. I figured I could fix the problem by simply installing appmenu-gtk.

So, run the following command to fix the issue:

sudo apt-get install appmenu-gtk

Cheers!

VLC does not support the audio or video format “h.264″. Unfortunately there is no way for you to fix this.”

All other media files game same error with different codec names. I couldn’t play anything in VLC. To fix the problem I installed package called libva1.

sudo apt-get install libva1

Cheers!