Limited System -> Administration menu

[Jatan]

Hi Everyone,

I have just joined this list, so I am not sure if this has been asked
before. I installed Ubuntu (its the best!!) on my Dell d610 laptop and
it was running great. I named the initial user as "jatan". So whenever I
logged in as that user, I was able to access all the menu items in the
System -> Administration menu. But for some days, that menu only has the
following 5 menu items: 
Device MAnager
Network Tools
Printing
System Log
System Monitor

I don't know what I changed which triggered this. I am not able to see
any other menu items (Synaptic, etc). How do I enable it again?

Also, whenever I click on the sound icon, it says "No volume control
GStreamer plugins and/or devices found". This also wasn't happening
before. 

Any ideas? Thanks a lot!

Jatan