[PLUG] Add/Remove Software error

[paras]

Hi all,

I am working on FC-9 with KDE-4.2.4.
I wan't to add some software. So I trying to use Add/Remove Software.
But when I select the package and click on Apply button, the error message
pop-ups,
"*No network connection available*. Please check your connections and try
again."

Under more details, I get this: "Cannot install when offline."

But there is no trouble with internet browsing.

One more think is I can install same package using "yum"

The out-put of "nm-tool" command is given below
------------------------------------------------------------------------------------------------
*NetworkManager Tool

State: disconnected

- Device: eth0
-----------------------------------------------------------------
  Type:              Wired
  Driver:            tg3
  State:             unmanaged
  Default:           no
  HW Address:        00:00:00:00:00:00

  Capabilities:
    Carrier Detect:  yes
    Speed:           100 Mb/s

  Wired Properties
    Carrier:         on*
--------------------------------------------------------------------------------------
Does anyone know how I can fix this?

Thanks In Advance.