I cant play songs..

Hello,
I am new ubuntu....just two days back i insatlled ubuntu 8.10....Firstly i thought its very cool software ...but i faced so many problems hope you people can resolve..
-->I Tried to install Netbeans it was not possible i tried following methods:
Method 1: Install NetBeans via Ubuntu Package Manager

The following section describe how to install the NetBeans IDE on Ubuntu via the Package Manager Utility provided by the operating system.

1. Setup the Source Repository

To install NetBeans via the Ubuntu Package Manager, ensure that the correct repository is listed in the source listing file. NetBeans is found inf the universe repository and Java is found in the multiverse repository.

Code:
sudo gedit /etc/apt/sources.list

Ensure that the following sources are added to the configuration file:
* deb http://za.archive.ubuntu.com/ubuntu/ intrepid universe
* deb-src http://za.archive.ubuntu.com/ubuntu/ intrepid universe
* deb http://za.archive.ubuntu.com/ubuntu/ intrepid-updates universe
* deb-src http://za.archive.ubuntu.com/ubuntu/ intrepid-updates universe
* deb http://za.archive.ubuntu.com/ubuntu/ intrepid multiverse
* deb-src http://za.archive.ubuntu.com/ubuntu/ intrepid multiverse
* deb http://za.archive.ubuntu.com/ubuntu/ intrepid-updates multiverse
* deb-src http://za.archive.ubuntu.com/ubuntu/ intrepid-updates multiverse

After the configuration file is updated, the package repository needs to updated with the following command:

Code:
sudo apt-get update
2. Install Required Software

To install Java version 6, the following command needs to be executed:

Code:
sudo apt-get install sun-java6-jdk sun-java6-plugin
3. Install Netbeans IDE

To install NetBeans, the following command needs to be executed. The package manager does not necessarily install the latest version of NetBeans. The package manager will install the latest NetBeans that is supported by Ubuntu.

Code:
sudo apt-get install netbeans
Method 2: Install NetBeans via Installer (Manual Download)

The following section describes how to install the NetBeans IDE on Ubuntu via a manual download. This method enables you to choose the version of NetBeans to install as well as the additional bundles available.

1. Setup the Source Repository

To install NetBeans via the Ubuntu Package Manager, ensure that the correct repository is listed in the source listing file. See Method 1 above. Java 6 is found in the multiverse repository.

Ensure that the following sources are added to the configuration file:
* deb http://za.archive.ubuntu.com/ubuntu/ intrepid multiverse
* deb-src http://za.archive.ubuntu.com/ubuntu/ intrepid multiverse
* deb http://za.archive.ubuntu.com/ubuntu/ intrepid-updates multiverse
* deb-src http://za.archive.ubuntu.com/ubuntu/ intrepid-updates multiverse
2. Install Required Software

To install Java version 6, the following command needs to be executed:

Code:
sudo apt-get install sun-java6-jdk sun-java6-plugin

The following command is used to ensure the correct version is used:

Code:
sudo update-java-alternatives -s java-6-sun
3. Install Netbeans IDE

To install NetBeans, download the appropriate installation file from the Official NetBeans Download Site. The version of NetBeans that was downloaded for this post is: NetBeans V6.5 - Full Bundle. (netbeans -6.5-ml-linux.sh)

Code:
sudo ./netbeans-6.5-ml-linux

After the command is executed and the sudo password is supplied, the following screen will display. It provides the user with some options on the bundled software packaged with the NetBeans installation.

But still i was not able to get the netbeans....for my project this is necessary so i cant switch to windows..
--> And another one..if i try to play songs...i will get followwing error
1)cannot insatll gstream 0.10 ffmpeg
2) i tried to insatll it through the syntatic manager in that i got following error
Could not mark all packages for installation or upgrade
gstream0.10-ffmpeg:
Depends:libgstreamer0.10-0(>=0.10.20-3)but 0.10.18-4ubuntu1 is to be insatlled