Applications menu and "Main menu"(alacarte) not working

Related Ubuntu forums thread:
http://ubuntuforums.org/showthread.php?t=416913

Related Launchpad bug report:
https://bugs.launchpad.net/ubuntu/+bug/104521

I've tried to ask for help in solving this issue on the Ubuntu forums but was unable to solve it successfully. Thus, I'm making a post here.

My issue:
About 4 to 5 hours ago, I was trying to install Gimp 2.2.14 from source. However, I had not done anything yet and was just reading the installation guide. I was pasting a command into Terminal(right-click mouse button) when Xserver crashed.

This is the error I received.
"Nautilus can't be used now, due to an unexpected error from Bonobo when attempting to locate the factory.Killing bonobo-activation-server and restarting Nautilus may help fix the problem."

When Xserver crashed, all my running programs vanished and my desktop was blank!
After which, I restarted the pc and went back to installing Gimp. A short while later, I discovered that I could not access "Accessories" or even "Main menu" from "System===>Preferences".

So, I posted in the forums for help and these are the steps I've tried so far:

1) Tried to start alacarte from Alt + F2. Alacarte didn't start.

2) Tried to start Alacarte from Terminal. Received following error messages:

user@user:~$ alacarte

Traceback (most recent call last):
File "/usr/bin/alacarte", line 36, in <module>
main()
File "/usr/bin/alacarte", line 32, in main
app = MainWindow(datadir, version, sys.argv)
File "/usr/lib/python2.5/site-packages/Alacarte/MainWindow.py", line 49, in __init__
self.editor = MenuEditor()
File "/usr/lib/python2.5/site-packages/Alacarte/MenuEditor.py", line 36, in __init__
self.__loadMenus()
File "/usr/lib/python2.5/site-packages/Alacarte/MenuEditor.py", line 46, in __loadMenus
self.applications.dom = xml.dom.minidom.parse(self.applications.path)
File "/usr/lib/python2.5/site-packages/_xmlplus/dom/minidom.py", line 1915, in parse
return expatbuilder.parse(file)
File "/usr/lib/python2.5/site-packages/_xmlplus/dom/expatbuilder.py", line 926, in parse
result = builder.parseFile(fp)
File "/usr/lib/python2.5/site-packages/_xmlplus/dom/expatbuilder.py", line 211, in parseFile
parser.Parse("", True)
xml.parsers.expat.ExpatError: no element found: line 1, column 0

3) Then, I was advised to try "sudo aptitude install python-xml python-lxml". That didn't work either: "Accessories" and "Main menu" still not working. (The person helping me, Pobega, thought it could be a Python or XML-related issue.)

4) Then, I was asked to try "sudo aptitude reinstall python2.5" . That too didn't resolve the "Accessories" and "Main menu" issue.

5) Suggested uninstalling Gimp and was asked to try "make uninstall Gimp" from /home/<user>/Desktop/gimp-2.2.14 So, Gimp 2.2.14 was uninstalled.

6) So, I was suggested to try this "sudo aptitude reinstall python2.5 gimp" Nope, that didn't do anything to fix my issue.

7) Was finally told that reinstalling Gnome or Ubuntu might be my only fix. :(